North Korea has moved into place a long-range rocket for a controversial launch later this month - amid reports it is also planning a nuclear test.

Pyongyang says the Unha-3 rocket, which it plans to launch between 12 and 16 April, will put a satellite into orbit.

But opponents of the move fear it is a disguised long-range missile test.

Meanwhile, South Korean officials say new satellite images suggest the North is preparing to carry out a third nuclear test.

The images show piles of earth and sand at the entrance of a tunnel at the Punggye-ri site, where tests of a nuclear bomb were previously carried out in 2006 and 2009, South Korea’s Yonhap news agency reports.

Although the land near the Fukushima nuclear reactors was heavily contaminated by the aerial release of radioisotopes, the majority of the radioactive releases drifted out over the Pacific. There, they were joined by substantial amounts of water that were discharged from the reactors directly into the ocean. A new study, based on data from a NOAA research vessel, takes a look at radioactivity levels near Japan a few months after the disaster. The data suggest that the highest estimates of radioactive discharges are likely to be accurate, but the rapid dilution of the water has kept the levels below the naturally occurring radioactivity.

Although the peak of discharge into the ocean occurred in early April, NOAA didn’t manage to get a vessel in place until June. For the first half of the month, the Ka’imikai-o-Kanaloa (Hawaiian for “Heavenly Searcher of the Sea”) sampled the waters and oceanic life off Japan (between 30km and 600km), all while releasing floats that helped researchers identify the predominate currents in the region. Most of the radioactivity was released in the form of cesium isotopes that have half-lives of over two years, so the time needed to get a vessel in place did not allow for a significant decay of the discharged material.

The operator of Japan’s crippled Fukushima nuclear plant has said damage to one of the reactors is much worse than previously thought.

A probe inserted into reactor two at the Fukushima Daiichi nuclear plant revealed lethal doses of radiation and that the level of cooling water inside was far lower than expected.

But operator Tepco says the plant remains in a cold shutdown.

The plant was severely damaged by the March 2011 earthquake and tsunami.

China and the US have agreed to co-ordinate their response to any “potential provocation” if North Korea goes ahead with a planned rocket launch, the White House says.

North Korea says the long-range rocket will carry a satellite. The US says any launch would violate UN resolutions and be a missile test.

US President Barack Obama and Chinese President Hu Jintao met on the margins of a nuclear summit in South Korea.

The launch is scheduled for April.

Its timing - between 12 and 16 April - is intended to mark the 100th anniversary of the birth of North Korea’s late Great Leader Kim Il-sung.

WASHINGTON — A classified war simulation held this month to assess the repercussions of an Israeli attack on Iran forecasts that the strike would lead to a wider regional war, which could draw in the United States and leave hundreds of Americans dead, according to American officials.

The officials said the so-called war game was not designed as a rehearsal for American military action — and they emphasized that the exercise’s results were not the only possible outcome of a real-world conflict.

But the game has raised fears among top American planners that it may be impossible to preclude American involvement in any escalating confrontation with Iran, the officials said. In the debate among policy makers over the consequences of any Israeli attack, that reaction may give stronger voice to those in the White House, Pentagon and intelligence community who have warned that a strike could prove perilous for the United States.

The results of the war game were particularly troubling to Gen. James N. Mattis, who commands all American forces in the Middle East, Persian Gulf and Southwest Asia, according to officials who either participated in the Central Command exercise or who were briefed on the results and spoke on condition of anonymity because of its classified nature. When the exercise had concluded earlier this month, according to the officials, General Mattis told aides that an Israeli first strike would be likely to have dire consequences across the region and for United States forces there.

US President Barack Obama has warned North Korea that it will “achieve nothing by threats or by provocations”.

The warning comes as Pyongyang prepares to launch a long-range missile which it says will put a satellite in orbit.

Mr Obama was speaking after talks in Seoul with South Korean President Lee Myung-bak, ahead of global summit on nuclear security.

The two leaders said North Korea risked further sanctions and isolation if it did not cancel its launch plans.

Mr Obama said Washington and Seoul were “absolutely united” that “bad behaviour” by North Korea would not be rewarded.

“North Korea knows its obligations and it must take irreversible steps to meet those obligations,” he said.

The launch will contravene an agreement Pyongyang reached last month which would have seen it receive food aid in exchange for a partial freeze on nuclear activities and an end to ballistics tests.

Mr Lee, who spoke alongside Mr Obama, said their countries had “agreed to respond sternly to any provocations and threats by the North and to continually enhance the firm South Korea-US defence readiness”.

But he said the international community stood ready to help North Korea improve the lives of its citizens if it chose a path of peace.

Mr Obama also criticised China, saying its refusal to challenge North Korea on the nuclear issue was not working as a policy.

As tensions rise over Iran’s nuclear program, a majority of Americans want Israel and the U.S. to pursue diplomacy over military action.

President Obama insists “all options are on the table” to stop Iran from developing a nuclear weapon. But Obama and American officials have cautioned Israel against a preemptive strike against Iran, urging diplomacy and sanctions instead. There is still a “window for diplomacy” to deter Iran’s nuclear development, Obama told Israeli Prime Minister Benjamin Netanyahu earlier this month. Netanyahu insists that Israel reserves the right to secure its own national security.

But only one in four Americans favor Israel launching a military strike against Iran’s nuclear program, according to a new University of Maryland poll. Seven out of 10 respondents believe the U.S. and other world leaders should continue to pursue negotiations with Iran. President Obama called for continued diplomacy in a joint press conference with British Prime Minister David Cameron on Wednesday. Cameron agreed.

Only one in five respondents believe a strike against Iran would delay its ability to develop a nuclear weapon for more than five years, according to the poll. And about half of Americans polled believe the conflict would go on for years.

Six in 10 respondents believe Iran is actively working to produce nuclear weapons. Nine in 10 believe Iran will eventually develop them. U.S. intelligence agencies continue to believe there is no evidence Iran has decided to build a bomb. The tensions over Iran’s nuclear program appear to be taking a toll. Last month, Iran topped Gallup’s “greatest enemy” list. Threatening Israel, announcements of its growing nuclear program and the possibility that Iran could disrupt the flow of oil all contributed to the antipathy, according to the poll.

President Obama challenged his Republican critics to make a case to the American people for a military strike against Iran’s nuclear facilities if they really believe that is the right course to follow, throwing down an election-year challenge to the men who are vying to succeed him and who say that his Iran policy has been too weak.

“This is not a game,” Mr. Obama said during a news conference at the White House timed to coincide with Super Tuesday voting in the Republican primaries in a number of crucial states. Mr. Obama gave a staunch defense of his administration’s actions to rein in Iran’s nuclear ambitions and said that tough sanctions put in place by the United States and Europe were starting to work and were part of the reason Iran had returned to the negotiation table.

“The one thing we have not done is we have not launched a war,” Mr. Obama said. “If some of these folks think we should launch a war, let them say so, and explain to the American people.”

Less than an hour after former Gov. Mitt Romney vowed to make Jerusalem his first foreign destination if elected president, one of his rivals for the Republican nomination, former House Speaker Newt Gingrich , went one better, promising to move the American Embassy from Tel Aviv to Jerusalem on “Day 1” of his prospective presidency.

Mr. Gingrich, speaking by satellite to some 13,000 people at the conference of the American Israel Public Affairs Committee, said that if elected, he would also immediately “initiate a strategy in the tradition of Reagan, Thatcher and Pope John Paul II to undermine and replace the Iranian dictatorship by every popular method short of war.”

“In a Gingrich administration, we would not keep talking while the Iranians keep building,” he said to strong applause.

“The red line is not the morning the bomb goes off, the red line is not the morning our intelligence community tells us they’ve failed once again,” he added. “The red line is now.”

While Mr. Romney’s campaign distributed an advance text of his remarks, and former Senator Rick Santorum appeared live at the conference to give a full speech, Mr. Gingrich spoke for just a couple of minutes and then said he would take questions from a panel. But there was no panel assembled as there had been for Mr. Romney. (Among the questions: what he remembers most of his visits to Israel – Mr. Romney managed to parlay that into policy, saying it was the Jerusalem stone, which he described as a symbol of the importance of a united capital). So Mr. Gingrich waxed extemporaneously about the Middle East.

“There’s something profoundly wrong with our entire approach to the region and our entire strategy for dealing with radical Islam,” he said, condemning the Obama Administration for “failing intellectually.”

“We need to be clear that the teaching of hatred, the recruiting of martyrs” are not “compatible with a peace process and we will not tolerate engaging in a process with people who engage in those behaviors.”

Defense Secretary Leon E. Panetta pledged to an influential pro-Israel lobbying group on Tuesday that if the pressure of diplomacy and sanctions failed to stop Iran from building a nuclear weapon, the United States was fully prepared to take military action as a last resort.

“Make no mistake: When all else fails, we will act,’’ Mr. Panetta told the American Israel Public Affairs Committee.

Mr. Panetta’s remarks tracked closely with those of President Obama, who spoke to the same group on Sunday, and were meant to drive home the president’s message that Israel could trust the United States in the growing confrontation with Iran. Like Mr. Obama, Mr. Panetta said that United States “does not bluff’’ and “we will keep all options, including military action,’’ on the table.

The defense secretary also appeared to allude to the hard-hitting Iran talk coming from the Republican presidential candidates, who spoke by video feed to Aipac on Tuesday. “In this town, it’s easy to talk tough,’’ Mr. Panetta said. “Acting tough is a hell of a lot more important.’’

But he declared: “No greater threat exists to the security of Israel and to the entire region and indeed to the United States than a nuclear-armed Iran.”

Israeli Prime Minister Benjamin Netanyahu has told US President Barack Obama that Israel must always remain “master of its fate”.

Meeting the Israeli leader at the White House, Mr Obama said a nuclear Iran would be an “unacceptable” development.

On Sunday, Mr Obama told a pro-Israel conference in Washington there had been too much “loose talk” of war with Iran.

Israel fears Iran is seeking to develop nuclear weapons, although Tehran insists its nuclear plans are peaceful.

“The bond between our two countries is unbreakable,” Mr Obama said, as the two leaders sat side-by-side in the Oval Office.

The president emphasised: “We believe there is still a window that allows for a diplomatic resolution,” but added that the US would consider “all options” in dealing with Iran.

Meanwhile, Mr Netanyahu said Israel “must have the ability to defend itself, by itself, against any threat”.

Benjamin Netanyahu: “My supreme responsibility… is to ensure that Israel remains the master of its fate”

The Obama administration’s Department of Energy, led by Steven Chu, has taken a “portfolio” approach to easing the country into a future in which we’re less reliant on fossil fuels. Instead of betting on a single technology to solve all our problems, the DOE has been pushing a mix of renewables, efficiency measures, and nuclear power. After having licensed the first new nuclear plant in decades, the DOE has now reached agreements with companies that are trying to develop an alternative to these large facilities.

Rather than building large, Gigawatt-scale reactor buildings, several companies are developing what are termed small, modular nuclear reactors that produce a few hundred Megawatts of power. These are typically designed to be sealed units that simply deliver heat for use either directly or to generate electricity. When the fuel starts to run down, the reactors will be shipped back to a central facility for refueling. Since they will never be opened on site, many of the issues associated with large plants don’t come into play.

The new agreements, set up with Hyperion Power Generation, SMR, and NuScale Power, will give the companies access to the DOE’s Savannah River National Lab, with the intention of having them develop sites there for a test installation. Ultimately, the test installations are intended to provide data that will go into the licensing of these new designs. Chu, in announcing the agreement, stated, “We are committed to restarting the nation’s nuclear industry and advancing the next generation of these technologies.”

North Korea has agreed to suspend its nuclear development in return for food aid . The country suffers from chronic food shortages and periodic famine, even though neighbors China and South Korea haven’t had such problems for many years. Why are the North Koreans always going hungry?

Poor growing conditions, fertilizer shortages, and general mismanagement. On the most basic level, the terrain and climate in North Korea aren’t great for farming. The country is mountainous, and the growing seasons are short. (North Korea is at approximately the same latitude as New England, but prevailing air currents make it even colder.) In defiance of nature, North Korea’s isolationist leaders decided in the 1950s that domestic farmers had to fulfill all the country’s food needs. They instituted intensive agricultural practices to maximize yield from their limited arable land, relying on heavy irrigation and copious pesticides, herbicides, and fertilizers. They scraped by for decades with only occasional famines, but the system totally collapsed in the 1980s, when the Soviet Union cut the supply of subsidized fossil fuels, from which many of the DPRK’s agricultural chemicals are derived .

When crop yields declined, the government tried to plug the gap by increasing acreage. They stripped hillsides of all natural vegetation and tried terraced agriculture. It worked for a little while, but heavy seasonal rains eventually eroded the new farms and filled the nation’s rivers, reservoirs, and irrigation canals with silt. Eventually, the land was no longer able to absorb the water from annual monsoons, and flooding became a chronic problem.

This is a whole new way to use the term “deterrence”. Maybe you were under the impression that America already has a deterrent against an Iranian nuclear threat, namely our arsenal of over 5,000 strategic nuclear warheads. Think again! Mr Loyola wants to deter Iran from trying to build a nuclear warhead. But that’s not all: he wants to deter Iran from failing to convince the entire world that it has definitely given up any effort to build a nuclear warhead. To do that, we need to have a “clear deterrent threat of military action”. In other words, we need to set a deadline for an attack on Iran if it has not entirely convinced us that it has given up trying to develop the technology to build nuclear weapons.

This is sort of like me trying to deter you from failing to say “uncle” by putting you in a headlock and displaying a clear deterrent threat to break your arm. Or, to be more charitable, like Russia deterring Georgia from failing to recognise the independence of South Ossetia by massing tank columns on the Georgian border. It’s not the way I would normally use the term “deterrence”, and threatening to launch a first strike on Iran is not what I would normally think of as “prudence and precaution”. But it’s clearly one way war hawks are going to present the Iranian situation going forward, so keep an eye out for it.

A senior US military official has said that the issue of food aid for North Korea is now linked to political conditions.

Admiral Robert Willard, commander of the US Pacific Fleet, made the comments to a Senate committee on Tuesday.

He said conditions being discussed for food aid resumption included talks on ending North Korea’s nuclear programme

This contradicts official US policy, where the nuclear programme is separate from the provision of food aid.

North Korea relies on international aid to feed its people.

“There are conditions that are going along with the negotiations with regard to the extent of food aid,” Adm Willard told the US Senate Armed Forces Committee.

He said “preconditions” for assistance “now include discussions of cessation of nuclearisation and ballistic missile testing and the allowance of IAEA perhaps back into Yongbyon [reactor]”.

In 2009, International Atomic Energy Agency inspectors were asked to leave Yongbyon as denuclearisation talks between North Korea and its dialogue partners - the US, China, Russia, South Korea and Japan - broke down.

North Korea has agreed to suspend uranium enrichment, as well as nuclear and long-range missile tests, following talks with the US.

The US State Department said Pyongyang had also agreed to allow UN inspectors to monitor its reactor in Yongbyon to verify compliance with the measures.

In return, the US is finalising 240,000 tonnes of food aid for the North.

The move comes two months after Kim Jong-un came to power following the death of his father, Kim Jong-il.

Correspondents say the move could pave the way for the resumption of six-party disarmament negotiations with Pyongyang, which last broke down in 2009.

Amid heightened tensions with the West over its nuclear program , Iran on Tuesday called for negotiations on a treaty banning nuclear weapons and condemned their production or possession as “a great sin.”

There were two ways to engage with Iran on its nuclear program , engagement or confrontation, the Iranian Foreign Minister, Ali Akbar Salehi, said in a statement to the Conference on Disarmament here in Geneva. He said that Iran, “confident of the peaceful nature of its nuclear program, has always insisted on the first alternative.”

Mr. Salehi’s statement came only days after the United Nations nuclear watchdog agency expressed concern over the possible military dimensions of Iran’s nuclear program. The watchdog, the International Atomic Energy Agency , offered its assessment after a visit to Iran by its inspectors in which Iran denied them access to military facilities linked to the nuclear program.

The I.A.E.A. reported in November that it had “credible” information that the facilities at Parchin, south west of the capital, Tehran, included an explosives containment chamber used for experiments that were “strong indicators” of possible nuclear weapons development.

Echoing sentiments expressed in speeches by Iran’s supreme leader, Ayatollah Ali Khamenei, Mr. Salehi denied the nuclear program had a military purpose, saying Iran would be a stronger country without nuclear arms.

“We do not see any glory, pride or power in the nuclear weapons, quite the opposite,” he said, adding that on the basis of a religious decree issued by Ayatollah Khamenei, “the production possession, use or threat of use of nuclear weapons are illegitimate, futile, harmful, dangerous and prohibited as a great sin.”

He said the existence of nearly 23,000 nuclear weapons in the world posed “the gravest threat” to sustainable international security and that as long as they existed there would always be a risk of their use and proliferation.

In the darkest moments of last year’s nuclear accident, Japanese leaders did not know the actual extent of damage at the plant and secretly considered the possibility of evacuating Tokyo, even as in public they tried to downplay the risks, an independent investigation into the accident disclosed on Monday.

The investigation by the Rebuild Japan Initiative Foundation, a newly created private policy organization, offered one of the most vivid accounts yet of how Japan teetered on the edge of an even larger nuclear crisis than the one that actually engulfed the Fukushima Daiichi Nuclear Power Plant. A team of 30 university professors, lawyers and journalists spent more than six months on an inquiry into Japan’s response to the triple meltdown at the plant, which followed a massive earthquake and tsunami on March 11 that shut down the plant’s cooling systems.

The team was granted extraordinary access, in part because of a strong public demand for greater accountability. Its members conducted interviews with more than 300 people including top nuclear regulators and government officials, as well as the prime minister during the crisis, Naoto Kan. It was assembled by the Rebuild Japan Initiative Foundation, a policy organization founded by a respected public intellectual, Yoichi Funabashi, a former editor in chief of the Asahi Shimbun, one of Japan’s biggest dailies.

An advanced copy of the report describes how Japan’s response was hindered at times by a debilitating breakdown in trust between the major actors: then Prime Minister Naoto Kan, the Tokyo headquarters of plant operator Tokyo Electric Power, known as Tepco, and the plant manager at the stricken Fukushima Daiichi Nuclear Power Plant. The conflicts helped produce confused flows of sometimes contradictory information in the early days of the crisis, the report said.

For much of the last year, the Republican candidates for president have hammered President Obama ‘s handling of the Middle East peace effort, hoping to drive a wedge between Mr. Obama and Jewish voters and other supporters of Israel over the issue of Israel’s security.

Now, the rising tensions over Iran’s nuclear ambitions — and the growing possibility of an Israeli-led strike on Iran’s facilities that could come as early as this summer — has once again brought the issue of Israel to the forefront of the presidential campaign.

The White House announced on Monday that Mr. Obama will host Binyamin Netanyahu, the Israeli prime minister, at the White House early next month. The meeting comes amid reports that the United States is cautioning Israel against launching a strike.

A statement from the White House said the visit was “part of the continuous and intensive dialogue between the United States and Israel and reflects our unshakeable commitment to Israel’s security.” Mr. Obama dispatched his national security adviser to Israel over the last several days to discuss the Iranian situation and other issues.

But Mr. Obama’s Republican rivals are likely to try to use the White House meeting on March 5 — which comes on the day before the Super Tuesday primaries — to renew their attacks on an administration they say has not done enough to help protect and support Israel.

Iran ’s government ordered a halt to oil exports to Britain and France on Sunday, in what may be only an initial response to the European Union decision to cut off Iranian oil imports and freeze central bank assets beginning in July.

Britain and France depend little on Iranian oil, however, so their targeting may be a mostly symbolic act, a function of the strong positions Paris and London have taken in trying to halt Iranian nuclear enrichment and bring pressure to bear on Syria, one of Tehran’s closest allies.

Tehran may also be reluctant, when its economy has been damaged by existing sanctions, to deprive itself of revenues from its larger European customers. At the same time, it may be seeking to divide the 27-nation European Union between those who depend on Iranian oil and those who do not.

Sunday’s order, according to the Mehr News Agency in Tehran, came from the Iranian oil minister, Rostam Qassemi, who had warned this month that Tehran would cut off oil exports to “hostile” European nations. On Sunday, the ministry spokesman, Ali Reza Nikzad-Rahbar, confirmed that shipments to Britain and France had been cut off, and said on the ministry Web site, “We have our own customers and have no problem to sell and export our crude oil to new customers.”

At the same time, according to the Mehr agency, an official at the Oil Ministry said Iran was seeking longer-term contracts of two to five years with other European nations.

Urging nations to draw “red lines against Iranian aggression,” Prime Minister Benjamin Netanyahu said Wednesday that the arrest of Iranians in Bangkok after a suspicious explosion and bombing attempts on Israeli diplomatic personnel in India and Georgia have exposed Iran ’s “acts of terror” to the world.

“These days, Iran’s acts of terror are clear to everyone,” he told Parliament. “Iran is disrupting world stability and hurting innocent diplomats in many countries. Countries around the world must condemn Iran’s terror operations and draw red lines against Iranian aggression. If not stopped, this aggression will spread to many countries.”

Israel has blamed Iran for two car bomb attacks targeting its diplomats on Monday, one in New Delhi which seriously injured an Israeli woman and three other people, and the second in Tblisi, the capital of Georgia, which was defused by police there after a local Israeli Embassy employee reported a noise under his car.

An explosion in Bangkok on Tuesday led authorities there to two Iranians who were arrested on suspicion that they were on their way to try to attack Israeli diplomats. One of the men lost at least one leg from the explosion. Israeli officials said the explosive device in Thailand was similar to those used in India and Georgia.

Iranian officials have rejected those accusations, saying that Israel is trying to besmirch Tehran, and Thai officials said it was too early to link what they found to what had occurred elsewhere.

In Iran, state television reported advances in its nuclear program on Wednesday. Iran says the program is for civilian use. Israel and most of the West believes the goal is to build nuclear weapons and Israeli is especially worried. It has been pressing the world to make sure Iran does not build such a weapon, threatening a military strike if all else fails.

Iran is to unveil a “new generation” of faster, more efficient uranium enrichment centrifuges, state television says.

President Mahmoud Ahmadinejad is due to make an announcement on Iran’s nuclear programme later.

Western countries fear that Iran is working towards making its own nuclear weapons.

Tehran denies this, saying its nuclear programme is only for energy production.

“Propulsion,” the nine-year-old says as he leads his dad through the gates of the U.S. Space and Rocket Center in Huntsville, Alabama. “I just want to see the propulsion stuff.”

A young woman guides their group toward a full-scale replica of the massive Saturn V rocket that brought America to the moon. As they duck under the exhaust nozzles, Kenneth Wilson glances at his awestruck boy and feels his burden beginning to lighten. For a few minutes, at least, someone else will feed his son’s boundless appetite for knowledge.

Then Taylor raises his hand, not with a question but an answer. He knows what makes this thing, the biggest rocket ever launched, go up. And he wants—no, he obviously needs—to tell everyone about it, about how speed relates to exhaust velocity and dynamic mass, about payload ratios, about the pros and cons of liquid versus solid fuel. The tour guide takes a step back, yielding the floor to this slender kid with a deep-Arkansas drawl, pouring out a torrent of Ph.D.-level concepts as if there might not be enough seconds in the day to blurt it all out. The other adults take a step back too, perhaps jolted off balance by the incongruities of age and audacity, intelligence and exuberance.

As the guide runs off to fetch the center’s director—You gotta see this kid!—Kenneth feels the weight coming down on him again. What he doesn’t understand just yet is that he will come to look back on these days as the uncomplicated ones, when his scary-smart son was into simple things, like rocket science.

This is before Taylor would transform the family’s garage into a mysterious, glow-in-the-dark cache of rocks and metals and liquids with unimaginable powers. Before he would conceive, in a series of unlikely epiphanies, new ways to use neutrons to confront some of the biggest challenges of our time: cancer and nuclear terrorism. Before he would build a reactor that could hurl atoms together in a 500-million-degree plasma core—becoming, at 14, the youngest individual on Earth to achieve nuclear fusion.

President Obama said Sunday that he did not believe Israel was preparing to attack Iran to disrupt its nuclear program and that diplomacy remained the “preferred solution” to resolving the standoff over what Western leaders believe is Tehran’s pursuit of nuclear weapons .

In an interview with Matt Lauer of NBC, broadcast before the Super Bowl on Sunday night, the president also said that administration officials “don’t see any evidence” that Iran had the “intentions or capabilities” to mount an attack on United States soil in retaliation for a strike on its nuclear facilities.

Asked by Mr. Lauer if he deserved a second term, Mr. Obama said he did, despite the slow economic recovery.

“I deserve a second term, but we’re not done,” Mr. Obama said. “We’ve made progress, and the thing right now is to just make sure we don’t start turning in a new direction that could throw that progress off.”

Much of the interview, however, focused on the issue of Iran.

Mr. Obama’s remarks appeared to be intended to ratchet down emotions after a series of alarming public statements and reports. Leon E. Panetta, the defense secretary, did not dispute a report last week by David Ignatius of the Washington Post that Mr. Panetta believed Israel might strike Iran this spring.

North Korea on Thursday issued a long list of strident demands, including the cancellation of joint American-South Korean military exercises, that it said South Korea should meet before ties could improve between the two Koreas.

By repeating demands that the South has already rejected, North Korea appeared to shift the blame to Seoul one day after an American assistant secretary of state, Kurt M. Campbell, urged it to improve ties with the government in Seoul before expecting a better relationship with Washington.

The Policy Department of the North’s influential National Defense Commission issued the nine demands in the form of a questionnaire.

JERUSALEM — A senior Israeli official said Thursday that the missile testing site near Tehran that was destroyed in a huge explosion three months ago was developing missiles with a range of some 6,000 miles aimed at the United States.

The assertion went far beyond what rocket experts have established about Iran’s missile capabilities, and American officials questioned its accuracy.

The Israeli official, Moshe Yaalon, a deputy prime minister and minister for strategic affairs, said the explosion, at a Revolutionary Guard missile base, hit a system “getting ready to produce a missile with a range of 10,000 kilometers.”

“That’s the Great Satan,” he said, invoking the term Iran often uses to refer to the United States. “It was aimed at America, not at us.”

Mr. Yaalon was trying to make the point that the Iranian nuclear program is not a threat only to Israel but, as he put it, “a nightmare for the free world.” He said that it was a concern to Arab states as well as to the United States and Israel.

American officials said they believed Mr. Yaalon’s assertions were at best premature, and at worst badly exaggerated.

North Korea on Friday credited the country’s new leader, Kim Jong-un , with spearheading past nuclear testing, adding to official efforts to portray the young son of the late leader Kim Jong-il as a confident military commander. The official Uriminzokkiri Web site said Friday that Mr. Kim had “frightened” the country’s enemies by commanding nuclear tests. North Korea tested nuclear devices in 2006 and 2009, but the Web site did not specify which tests Mr. Kim oversaw.

Japan could allow nuclear reactors to operate for up to 60 years if they pass safety checks, the government said Wednesday, already revealing a loophole in recently announced plans to cap their lifespans at 40 years. Chief Cabinet Secretary Osamu Fujimura told reporters on Wednesday that the 40-year cap on reactors, announced earlier this month, will still apply in principle — but operators will likely be allowed a single 20-year extension for each reactor, providing they meet strict safety standards.

The longer limit comes amid heightened concerns over the country’s aging reactors following the disaster at the Fukushima Daiichi Nuclear Plant, where the oldest reactor was 40 years old and likely had inferior safeguards against severe accidents. According to the Ministry of Trade, 13 reactors in Japan will hit the 40-year limit in the next decade, excluding the six reactors at the Fukushima Daiichi plant damaged after an earthquake and tsunami on March 11.

Meanwhile, lengthening the operating life of its nuclear reactors could postpone Japan’s promised phase-out of nuclear power. Even if no more new reactors come online in Japan, allowing its newest unit to operate for 60 years would mean Japan would not become nuclear-free until 2069.

The escalating confrontation with Iran poses a major new political threat to President Obama as he heads into his campaign for re-election, confronting him with choices that could harm either the economic recovery or his image as a firm leader.

Sanctions against Iran’s oil exports that the president signed into law on New Year’s Eve started a fateful clock ticking. In late June, when the campaign is in full swing, Mr. Obama will have to decide whether to take action against countries, including some staunch allies, if they continue to buy Iranian oil through its central bank.

After fierce lobbying by the White House, which opposed this hardening in the sanctions that have been its main tool in pressuring Tehran, Congress agreed to modify the legislation to give Mr. Obama leeway to delay action if he concludes the clampdown would disrupt the oil market. He may also invoke a waiver to exempt any country from sanctions based on national security considerations.

But using either of those escape hatches could open the president to charges that he is weak on Iran, which is viewed by Western powers as determined to build a nuclear weapon. Republican candidates, led by Mitt Romney, have threatened to use military action to prevent Tehran from building a bomb, and have criticized Mr. Obama for not doing enough to stop it from joining the nuclear club.

Prime Minister Yoshihiko Noda said Friday that Japan had yet to decide whether it would reduce oil imports from Iran , continuing to send mixed signals in response to an American request to join in sanctions against the Iranian nuclear program .

Japanese leaders have seemed to flip-flop since Treasury Secretary Timothy F. Geithner visited Tokyo on Thursday and requested that Japan join efforts to pressure Iran to end what Western governments say is a program to develop nuclear weapons . The West has been engaged in an increasingly tense standoff with Iran over the nuclear program, which Tehran insists is for peaceful purposes.

While the Japanese finance minister expressed support for the sanctions after meeting with Mr. Geithner, the government’s chief cabinet secretary, Osamu Fujimura, appeared to pull back later in the day by saying that Japan had yet to make a final decision.

Iran will in the “near future” start enriching uranium deep inside a mountain, a senior Iranian official said Sunday, a move likely to further antagonize Western powers that suspect Tehran is seeking nuclear weapons capability.

A decision by the Islamic Republic to conduct sensitive atomic activities at an underground site — offering better protection against any enemy attacks — could complicate diplomatic efforts to resolve the long-running dispute peacefully.

Iran has said for months that it is preparing to move its highest-grade uranium refinement work to Fordow, a facility near the Shiite Muslim holy city of Qum in central Iran, from its main enrichment plant at Natanz.

The United States and its allies say Iran is trying to build bombs, but Tehran insists its nuclear program is aimed at generating power and for medical purposes.

North Korea ’s state-run television called its young untested leader, Kim Jong-un , a “military genius” on Sunday and showed him driving a tank, sitting in the cockpit of a warplane, and interacting with soldiers in a youthful display of camaraderie that was unlike the style of his late father.

The broadcast, a documentary on North Korea’s Central TV, also claimed that Mr. Kim, believed to be in his late 20s, oversaw the April 2009 test-launching of the country’s long-range rocket.

“I had determined to enter a war if the enemies dared to intercept” the rocket, he said in the program.

The program appeared to be part of North Korea’s frenzied campaign to burnish Mr. Kim’s credentials as a leader who can command its army of 1.2 million soldiers, which is one of the world’s largest armed forces and is crucial to his consolidation of power.

Mr. Kim took over after his father, the longtime dictator Kim Jong-il, died on Dec. 17. Late last month, he became supreme commander of the military, officially taking on the first of his father’s several top military and party posts.

North Korea’s propaganda campaign has since billed him as the “great successor” of his father’s songun, or “military first,” policy, which emphasizes military might. But the North’s development of nuclear weapons and tests of long-range missiles have brought economic sanctions that have deepened the country’s isolation and poverty.

Sunday’s documentary began with Mr. Kim riding a white horse, as his father, Kim Jong-il, often did in propaganda murals in North Korea. It was unclear when and where much of the video had been shot.

Mr. Kim was believed to have been groomed as successor at least from 2008, when his father suffered a stroke. He was officially unveiled as heir the next year, when he was made a four-star general and vice chairman of the ruling Workers’ Party’s Central Military Commission.

Although he is said to have graduated from the top military academy in Pyongyang, there is no indication that he had served in the army.

The North Korean media have been busy filling in the gaps in his military resume, claiming that he wrote his first thesis on military strategy when he was 16. During his New Year’s Day inspection of a tank division, he participated in a firing exercise, “making the New Year’s first sound of gunfire,” the documentary said.

Unlike his father, who usually stood solemnly during such inspections and was kept at a reverential distance from soldiers unless he took group pictures with them, Mr. Kim was seen laughing and clutching the hands of army officers and soldiers.

His father, Kim Jong-il, rarely made public appearances for three years after his own father, North Korea’s founding president, Kim Il-sung, died in 1994, and even when he did, he always wore a grim expression. He was said to be in mourning during this time.

But Kim Jong-un has lost no time establishing his public bona fides as a leader. The documentary was broadcast on what is believed to be his birthday. He is believed to have turned 28, 29 or 30 on Sunday. North Korea has not announced his exact birth date, and the day’s official news reports did not mention the birthday.

Japan said Friday that it will set more stringent age limits on nuclear reactors and require operators to prepare for severe accidents as part of legal changes in the wake of the nuclear crisis at Fukushima. The age limit could also be a step toward fulfilling a government promise to eventually phase out nuclear power in the quake-prone nation. Japan already requires utilities to conduct safety checks on reactors at 30 years, and again at 40 years, to stay in operation. Fresh legislation will set the legal lifespan of reactors at 40 years, though the government will still approve extensions on a case-by-case basis. Excluding the six damaged reactors at the Fukushima Daiichi plant, 13 others in Japan will hit the 40-year limit in the next decade, according to the Ministry of Trade.

European countries have taken their boldest step so far in the increasingly tense standoff with Iran over its nuclear program , agreeing in principle to impose an embargo on Iranian oil, French and European diplomats said on Wednesday.

A final decision by the European Union will not come before the end of January and would be carried out in stages to avoid major disruptions in global oil supplies. But the move by some of Iran’s most important oil customers appears to underscore the resolve of Western allies to impose on Iran the toughest round of sanctions to date, increasing pressure on Tehran to stop enriching uranium and negotiate an end to what Western leaders argue is an accelerating program to build a nuclear bomb.

France’s nuclear watchdog has called on the country’s 58 power plants to make safety improvements quickly, almost 10 months after the Fukushima disaster.

But it says none of the reactors needs to be shut down, following stress tests carried out in the wake of the Japanese earthquake and tsunami.

The watchdog estimates the changes would cost tens of billions of euros.

France obtains 75% of its electricity from nuclear power and the industry’s future has become a political issue.

The opposition Socialists want to reduce the country’s reliance on nuclear power and have agreed to phase out 24 reactors as part of a pact criticised by the ruling UMP party ahead of presidential elections.

North Korea on Sunday vowed an all-out push to improve the economic life of its impoverished people, criticized South Korea and rallied internal support for Kim Jong-un in a New Year’s statement that revealed the challenges the young new leader faces.

“The whole party, the entire army and all the people should possess a firm conviction that they will become human bulwarks and human shields in defending Kim Jong-un unto death,” said a joint editorial carried by the official newspapers of the party, the Korean People’s Army and the socialist youth league.

Outside analysts scrutinize the North’s annual joint New Year’s editorial, which is roughly the equivalent of the State of the Union speech in the United States. This year’s was Pyongyang’s first since Mr. Kim took the helm of the regime after the Dec. 17 death of his father, the long-time dictator, Kim Jong-il. Analysts looked for clues on where the regime was headed during this sensitive transfer of power to the relatively inexperienced leader.

‘‘Rather than offering a new policy, North Korea is sticking to its old policy line under the pretext of honoring the dying wishes of Kim Jong-il,’’ the Unification Ministry, a South Korean government agency in charge of relations with North Korea, said in a report analyzing the North Korean editorial. ‘‘It focuses on reviving the economy and building solidarity around Kim Jong-un.’’

North Korea’s real focus this year appears to be on building “a Stalinist monolithic dictatorial system” with Kim Jong-un as a new leader, said Cheong Seong-chang, an analyst at Sejong Institute, after studying the editorial. “With an intense workload at home, the regime is unlikely to try to improve ties with South Korea or the external world.”

Mr. Kim, believed to be in his late 20s, took over as North Korea entered a year in which it will mark the centenary of the April 15 birth of Kim Il-sung, the national founder, Mr. Kim’s grandfather and a god-like figure among North Koreans. Before his death, Kim Jong-il had promised that in 2012, North Korea would enter a new era as a “great and prosperous nation.”

Kim Jong-il had sought to justify his family’s dynastic rule by stirring a nationalistic pride with his development of nuclear weapons . But his goal of improving the living standards for people in the country had eluded him, partly because the nuclear weapons and long-range missile tests brought a wave of international sanctions.

Iranian scientists have produced the nation’s first nuclear fuel rod, a feat of engineering the West has doubted Tehran capable of, the country’s nuclear agency said Sunday.

The announcement marks another step in Tehran’s efforts to achieve proficiency in the entire nuclear fuel cycle — from exploring uranium ore to producing nuclear fuel — despite U.N. sanctions and measures by the U.S. and others to get it to halt aspects of its atomic work that could provide a possible pathway to weapons production.

Tehran has long said it is forced to seek a way to manufacture the fuel rods on its own, since the sanctions ban it from buying them on foreign markets. Nuclear fuel rods are tubes containing pellets of enriched uranium that provide fuel for nuclear reactors.

Iran’s atomic energy agency’s website said the first domestically made rod has already been inserted into the core of Tehran’s research nuclear reactor. But it was unclear if the rod contained pellets or was inserted empty, as part of a test.

“Scientists and researchers at the Atomic Energy Organization of Iran have succeeded in producing and testing the first sample of a nuclear fuel rod,” said the announcement.

Iranian President Mahmoud Ahmadinejad has hit back at the US, after Washington introduced new sanctions against Iran’s central bank.

Mr Ahmadinejad said the bank was strong enough to defeat “enemy plans”.

The sanctions - which cut off from the US financial system foreign firms that do business with the central bank - are part of a defence bill signed by President Barack Obama on Saturday.

They will take hold after a warning period of up to six months.

According to a statement quoted by the state-run Irna news agency , Mr Ahmadinejad said the central bank was “the backbone” of the country in facing outside pressure should have the strength and confidence “to thwart enemy plans”.

The new US sanctions come at a times of heightened tension over the Iranian nuclear programme.

Western powers say Tehran is seeking to acquire a nuclear weapons capability, but Iran insists the programme is purely for energy and medical purposes.

There have been concerns that the sanctions against the Iranian central bank could force up the price of oil.

The bill, which was passed by wide majorities in both houses of Congress, gives the president the power to grant a six-month grace period to give oil markets time to factor them in.

North Korea announced on Friday that there would be no change in its policy under its new leader, Kim Jong-un , striking a characteristically hostile posture with a threat to punish President Lee Myung-bak of South Korea for “unforgivable sins.”

The statement from the National Defense Commission, North Korea’s highest decision-making body, marked the country’s first official pronouncement to the outside world since the regime upheld Mr. Kim as its supreme leader on Thursday. His elevation came a day after the state funeral of his father, the long-time dictator Kim Jong-il .

“We declare solemnly and confidently that the foolish politicians around the world, including the puppet group in South Korea, should not expect any change from us,” said the statement. “We will never deal with the traitor group of Lee Myung-bak.”

The commission said it was “entrusted by the party, state and military” to issue the “principled stance.” The statement was carried by the Korean Central News Agency, the regime’s official mouthpiece to the outside world.

It directed its wrath at President Lee, whose government refused to express official condolences to North Korea and allowed only two private delegations to visit Pyongyang during “the great funeral of the nation.” It also criticized South Korea’s move to place its military on heightened vigilance and conservative South Korean activists’ launching of balloons that carried leaflets into the North.

By returning swiftly to its more typical bellicose form after two weeks of mourning, North Korea appeared to demonstrate a confidence that the transition of power in Pyongyang was going smoothly. But the strident rhetoric was also a sign that the regime, as it often has, was using perceived tensions with the outside world to rally its military and people behind the new leader during a sensitive transition.

“By taking a confrontational stance with the external world, North Korea seeks to solidify its internal cohesion as it tries to establish Kim Jong-un as leader,” said Kim Yong-hyun, a North Korea expert at Dongguk University in Seoul. “At the same time, it is pressuring the South to change its policy.”

What does a sudden evacuation look like? After everyone is gone, what happens to the places they've abandoned? National Geographic Magazine sent Associated Press photographer David Guttenfelder to the nuclear exclusion zone around Japan's Fukushima Daiichi power plant to find out. Evacuated shortly after the March 11 earthquake and tsunami led to a nuclear radiation crisis, the area has been largely untouched, with food rotting on store shelves and children's backpacks waiting in classrooms. The area may face the same fate as the town of Pripyat, Ukraine after the Chernobyl disaster 25 years ago. This isn't the first time Guttenfelder has gotten a rare glimpse of a place few see, as The Big Picture featured his photographs of North Korea in an earlier post. Collected here are Guttenfelder's haunting images just released of a place abandoned, and of people dealing with the loss.

The Japanese government told the operator of the ravaged Fukushima Daiichi nuclear power plant on Tuesday to consider accepting temporary state control in return for a much-needed injection of public funds, in effect proposing an interim nationalization of the struggling utility.

The order came after Tokyo Electric Power requested ¥689.4 billion, or $8.8 billion, in government aid to help pay for its response to the nuclear accident at its Fukushima site. The calamity, caused by the March 11 earthquake and tsunami, forced the evacuation of more than 100,000 people and led to a massive radiation leak.

The utility may have to pay ¥4.5 trillion in compensation payments by 2013, a government panel said in October, a sum that threatens to render the company insolvent.

The company will also most likely be forced to decommission all six nuclear reactors at Fukushima Daiichi at a huge cost, while the future of four other reactors at a second site is also on the line after a national outcry over the disaster.

Meeting with Tokyo Electric executives Tuesday, the Japanese trade minister, Yukio Edano, urged the utility to consider options including ceding control to the government.

An assertion by Defense Secretary Leon E. Panetta that Iran could have a nuclear weapon as soon as next year was based on a highly aggressive timeline and a series of actions that Iran has not yet taken, senior Pentagon officials said Tuesday.

In an interview broadcast Monday on “CBS Evening News,” Mr. Panetta was asked whether Iran could have a nuclear weapon in 2012.

“It would be sometime around a year that they would be able to do it,” he said. “Perhaps a little less.”

Mr. Panetta said the country’s ability to become a nuclear-weapons state could be accelerated if there was “a hidden facility somewhere in Iran that may be enriching fuel.”

He also restated American policy: that it would be unacceptable for Iran to have nuclear weapons , and that no options, including military action, had been taken off the table to prevent that from happening.

“The United States does not want Iran to develop a nuclear weapon,” Mr. Panetta said. “That’s a red line for us. And it’s a red line, obviously, for the Israelis.”

But on Tuesday, George Little, the Pentagon press secretary, said Mr. Panetta’s comments should not be taken as a prediction that Iran would have a nuclear weapon within a year.

On Thursday, the US Nuclear Regulatory Commission voted to approve a new nuclear reactor design, the AP1000 from Westinghouse. As Energy Secretary Steven Chu put it, the “decision certifying the AP1000 reactor design marks an important milestone towards constructing the first U.S. nuclear reactors in three decades.” The administration has already offered over $8 billion in loan guarantees to a project in Georgia that would feature two of these reactors as part of its push for domestic, low-carbon energy.

The Westinghouse design is a pressurized water reactor that includes numerous features that would allow it to continue to cool the reactors even if the site were to lose power—a key design feature, given what happened at Fukushima. Mindful of public perception, the company’s website for the design features an entire section that provides a timeline for shutdown following a blackout.

It has been several decades since the US last built a nuclear reactor, and a lot of the country’s existing facilities are pushing the edge of their designed lifespans. A significant amount of new construction is going to be needed if the country is to retain nuclear as a source of low-carbon baseline power. At the same time, the lack of recent construction leaves us without a good picture of the economics of building new plants in the US, something the Georgia project could help clarify.

Decommissioning the wrecked reactors at the Fukushima Daiichi nuclear plant will take 40 years and require the use of robots to remove melted fuel that appears to be stuck to the bottom of the reactors’ containment vessels, the Japanese government said on Wednesday.

The predictions were contained in a detailed roadmap for fully shutting down the three reactors, which suffered meltdowns after an earthquake and tsunami struck the plant on March 11 . The government had previously predicted it would take 30 years to clean up after the accident at Fukushima, the world’s worst nuclear disaster since Chernobyl in 1986.

The nuclear crisis minister, Goshi Hosono, acknowledged that no country has ever had to clean up three destroyed reactors at the same time. Mr. Hosono told reporters the decommissioning faced challenges that were not totally predictable, but “we must do it even though we may face difficulties along the way.”

The plan’s release follows last week’s declaration by Prime Minister Yoshihiko Noda that the plant had been put into the equivalent of a “cold shutdown,” a stable state that suggested the runaway reactors had finally been brought under control. Critics, however, immediately challenged that statement, saying it was impossible to call the reactors stable when their fuel had melted through the inner containment vessels, and appeared to be attached to the concrete bottom of outer containment vessels.

Still, the government appears ready to move ahead with the next stage of the cleanup. According to Wednesday’s roadmap, the plant’s operator, Tokyo Electric Power, will spend the next two years removing spent fuel rods from storage pools located in the same buildings as the damaged reactors. At least one of those pools, which are highly radioactive, was exposed by hydrogen explosions that destroyed the reactor buildings in the first days of the accident.

The most technically challenging step will be removing the melted fuel, a process that the government said will take 25 years and require new types of robots and other new technologies that have not even been developed yet. After the removal, fully decommissioning the reactors will take another 5 to 10 years, according to the roadmap.

The crippled nuclear reactors at Japan's Fukushima power plant have finally been stabilised, Prime Minister Yoshihiko Noda has announced.

An earthquake and tsunami in March knocked out vital cooling systems, triggering radiation leaks and forcing the evacuation of thousands of people.

Mr Noda's declaration of a "cold shutdown" condition marked the stabilisation of the plant.

The government says it will take decades to dismantle it completely.

The six-reactor Fukushima Daiichi nuclear plant was badly damaged by the 11 March earthquake and tsunami. Blasts occurred at four of the reactors after the cooling systems went offline.

Workers at the plant, which is operated by Tokyo Electric Power Company (Tepco), have been using sea water to cool the reactors. Waste water has built up and some contaminated liquid has been released into the sea.

A 20km (12m) exclusion zone remains in place around the plant.

Nine months after the devastating earthquake and tsunami knocked out cooling systems at the Fukushima Daiichi nuclear plant, causing a meltdown at three units, the Tokyo government is expected to declare soon that it has finally regained control of the plant’s overheating reactors.

Iran said Friday that it had formally complained to the United Nations Security Council about what it called the hostile and aggressive behavior of the United States in sending a sophisticated radar-evading spy drone over Iranian territory, one that Iran’s military said it had intercepted and captured last weekend.

The complaint, which appeared to have been made more for its propaganda value than for any Iranian hope of Security Council action, was announced a day after Iran showcased what it described as the captured drone on national television, as if it were a war trophy. Members of Iran’s Islamic Revolutionary Guards Corps were shown displaying a bat-winged aircraft on a platform bedecked with anti-American slogans and a mock American flag with skulls instead of stars.

American officials reviewing the footage have declined to confirm or deny that it showed the same model as the RQ-170 Sentinel surveillance aircraft that they have acknowledged was lost recently by C.I.A. controllers based in Afghanistan, a lapse attributed to an unspecified technical malfunction. But military experts have said privately that the Iranians appear to have an RQ-170, one of the Pentagon’s most technologically advanced reconnaissance drones.

How that happened remained unclear. Iran has asserted that it captured the aircraft via a cyberattack, saying its armed forces detected the drone on Sunday over northern Iran and were able to guide it to a safe landing about 155 miles from the Afghanistan border.

The loss of the drone is a potentially significant intelligence setback for the United States and has further elevated tensions with Iran, which were already high over Western suspicions that the Iranians are secretly developing a nuclear weapon despite their denials.

Iran’s complaint, submitted to the Security Council by the Iranian ambassador, Mohammad Khazaee, denounced what he called “the provocative and covert operations against the Islamic Republic of Iran by the U.S. government, which have increased and intensified in recent months.”

In the complaint, which Iranian news agencies reported, the ambassador said that as part of the trend “an American RQ-170 unmanned spy plane, bearing a specific serial number, violated Iran’s airspace.” He said Iran “strongly protests such hostile and aggressive moves and warns about harmful consequences of the repetition of such actions.”

It was considered highly unlikely that the Council would punish the United States, one of the five permanent members with veto power.

Iran’s Islamic hierarchy also sought to exploit what it considered the propaganda value of the showcased drone by making it the subject of the Friday Prayer address at Tehran University, often used to send messages to Iran’s foreign adversaries. The cleric who led the service, Kazzem Sediqi, praised the armed forces for capturing “the United States’ most advanced spying tool,” according to the semiofficial Fars News Agency.

American officials have said the use of the RQ-170 was part of a stepped-up operation to monitor Iran’s suspect nuclear sites. Western suspicions about Iran’s uranium enrichment program grew after the International Atomic Energy Agency, the nonproliferation arm of the United Nations, last month issued an incriminating report that said Iran needed to explain evidence that it may be working on a nuclear weapon. Iran has repudiated the report as fiction.

The drone footage on Iranian television on Thursday coincided with a diplomatic protest lodged with the ambassador from Switzerland, who represents American interests in Iran. The State Department confirmed on Friday that Iran’s Foreign Ministry had summoned the ambassador from Switzerland, but a department spokeswoman, Victoria Nuland, declined to specify what had been discussed.

Myanmar has denied it had been cooperating with North Korea on nuclear weapons technology, the first time it has commented on such speculation. The weekly newspaper Pyi Myanmar quoted the Parliament speaker, Thura Shwe Mann, left, as telling reporters last week that the armed forces of the two countries cooperated militarily, but “it was not on nuclear cooperation as is being alleged.” The newspaper said he made the comments after meeting with Secretary of State Hillary Rodham Clinton. Mrs. Clinton, who visited Myanmar last week, publicly called on Myanmar to “sever illicit ties to North Korea,” which officials said had included work on ballistic missiles and, possibly, nuclear technology.

A Saudi prince, in a remark designed to send chills through the Obama administration and its allies, suggested that the kingdom might consider producing nuclear weapons if it found itself between atomic arsenals in Iran and Israel.

The prince, Turki al-Faisal, who has served as the Saudi intelligence chief and as ambassador to the United States, made the comment on Monday at a Persian Gulf security forum in Riyadh, Saudi Arabia. The remark confirmed Western fears about the potential for an arms race in the Middle East if Iran moves to produce a nuclear weapon.

But it also reflected the hardening views among the Persian Gulf’s Arab states that they must rely on themselves — and not just on Western protection — as tensions with Iran grow worse.

Kuwaiti authorities are pressing ahead with several prosecutions against people accused of being Iranian spies, and Bahrain’s rulers contend that a cell linked to Iran sought to attack the Saudi Embassy.

Meanwhile, the United Arab Emirates is close to finishing a pipeline that would carry oil directly to Indian Ocean shipping lanes, bypassing the choke point at the Strait of Hormuz, which Iran has at times threatened to shut off to shipping.

In meetings last week, Arab envoys from the gulf agreed to study proposals to pool their military forces into a regional command, in an apparent reply to Iran’s expanding land and sea powers.

Prince Turki said at the forum on Monday that an Iranian quest for nuclear weapons and Israel’s presumed nuclear arsenal might force Saudi Arabia to follow suit. Most defense analysts believe that Israel has nuclear weapons, but it has refused to confirm or deny their existence.

“It is our duty toward our nation and people to consider all possible options, including the possession of these weapons,” Prince Turki was quoted as saying.

Iran enacted legislation on Monday to downgrade relations with Britain, in retaliation for intensified sanctions imposed by Western nations last week to punish the Iranians for their suspect nuclear development program. Britain promised to respond “robustly.”

New research has found that radioactive material in parts of north-eastern Japan exceeds levels considered safe for farming.

The findings provide the first comprehensive estimates of contamination across Japan following the nuclear accident in 2011.

Food production is likely to be affected, the researchers suggest.

The results are reported in the Proceedings of National Academy of Sciences (PNAS) journal.

In the wake of the accident at Japan's Fukushima nuclear power plant, radioactive isotopes were blown over Japan and its coastal waters.

Fears that agricultural land would be contaminated prompted research into whether Japanese vegetables and meat were safe to eat.

An early study suggested that harvests contained levels of radiation well under the safety limit for human consumption.

Mohammad Javad Larijani never finished his mathematics studies at Berkeley. Instead, he became one of the quotable, English-speaking, official defenders of Iran’s Islamic Revolution.

He was a 29-year-old graduate student in 1979, with an office that overlooked the San Francisco Bay, when he abruptly dropped his dissertation work and left the University of California, Berkeley, to return home, where revolutionary clerics were overthrowing the shah’s American-backed government. The son of an important ayatollah, Mr. Larijani became a prominent member of the new Islamic government, which valued him for his conservative religious upbringing and his fluency in the language of the country his contemporaries were calling the Great Satan.

Now 61, Mr. Larijani is still engaged in the work of seeking to rebut Iran’s critics, conducting a public-relations battle through overseas panel debates, newspaper interviews and television appearances. He has calmly faced questioning by journalists like Charlie Rose, Fareed Zakaria and Christiane Amanpour.

Whether he has succeeded in altering any American opinions about Iran is questionable. But even Mr. Larijani’s critics say he has a smooth, urbane delivery and a rational demeanor that contrast with the bombast of some other Iranian leaders who rage against the United States.

“He is someone who is quite often used as the diplomatic face of Iran,” said Hadi Ghaemi, head of the International Campaign for Human Rights in Iran, an advocacy group based in New York, who has no fondness for Mr. Larijani and has verbally dueled with him. “He is very well versed in putting Iran in a good light.”

Mr. Larijani also is a member of an extremely powerful conservative religious family in Iran, whose brothers include the speaker of the Parliament and the head of the judiciary.

With his current title of secretary general of Iran’s High Council for Human Rights, Mr. Larijani was in New York recently for meetings at the United Nations, where he sought to repudiate a report by the special rapporteur for human rights in Iran, Ahmed Shaheed, who said the Iranian government had engaged in a “pattern of systemic violations” of citizens’ rights. But he also found himself on the receiving end of many other questions, including new suspicions raised by a United Nations report about Iran’s nuclear program, Iranian antipathy toward Israel and its increasingly acrimonious tensions with the United States, highlighted by accusations of an Iranian plot to kill Saudi Arabia’s ambassador to Washington.

Mr. Larijani says Iran’s nuclear work is peaceful and a proud national accomplishment, the United Nations report is a joke, Israel is a project that has failed, the Saudi plot accusation is fantasy fiction and the United States needs to accept that Iran is a different type of democracy.

Low levels of radioactive particles have been detected in the Czech Republic and elsewhere in Europe, the UN nuclear agency has said.

The iodine-131 particles do not pose a public health risk, the International Atomic Energy Agency said.

The body said it was trying to work out where the particles had come from but said it did not believe the source was Japan's stricken Fukushima plant.

It said the Czech Republic had first informed them of the raised levels.

"The IAEA believes the current trace levels of iodine-131 that have been measured do not pose a public health risk and are not caused by the Fukushima Daiichi nuclear accident in Japan," the body said in a statement.

It said iodine-131 was a short-lived radioisotope with a radioactive decay half-life of about eight days.

The Czech nuclear security authority said it had been detecting radioactive iodine-131 at a number of monitoring stations since late October and had informed the IAEA to see if it could identify the source, Reuters reports.

Russia on Wednesday sharply dismissed calls for further sanctions against Iran in the aftermath of a new United Nations report on suspect Iranian nuclear activities, signaling the Kremlin’s departure from the cooperation on Iran that was a hallmark of the “reset” in relations with the United States.

After insisting for weeks that water collected from reactor buildings at the stricken Fukushima Daiichi nuclear plant posed no threat to human health once it was decontaminated, a Japanese government official poured himself a glass of the liquid and drank it on live television on Monday.

The water gulped down by the official, Yasuhiro Sonoda, came from the flooded basements of two reactor buildings at the plant, which was severely damaged when a tsunami struck the Japanese coast in March.

As the Japanese newspaper Asahi Shimbun reported, the safety of the water drained from the reactor buildings is an issue because the plant’s operator, Tokyo Electric Power Company, wants to pump it out to sea, despite objections from local governments and fishing cooperatives in the area.

In a report on Mr. Sonoda’s stunt, Japan’s state broadcaster NHK explained that the power company and Japan’s nuclear safety agency announced last month that the level of radioactive cesium in the decontaminated water was so low that it was safe for bathing and would pose no threat to the environment. By Japanese government standards for radiation, desalinated water that is safe enough to swim in is also safe to drink.

The party’s hawkishness was evident last week as five major Republican rivals campaigned in Iowa. In an interview outside Des Moines, Gov. Rick Perry of Texas was asked whether he would back a pre-emptive Israeli strike on Iran’s nuclear program, and he then told CNN he would support Israeli efforts “up to and including military action.”

Rick Santorum, the former Pennsylvania senator, described Iran as an “enemy” on Friday night in Des Moines at a dinner of almost 1,000 of the state’s most important Republican activists. In an interview, Mr. Santorum said that he would “stand shoulder to shoulder” in support of Israel if it launched a pre-emptive attack and that he would also back direct American military support if requested by Israel.

The issue holds particular resonance now amid numerous reports that United Nations inspectors will state this week that Iran has moved closer to being capable of building a nuclear weapon, and as Israel has been debating a more confrontational posture toward Iran.

Broadly within the party, the focus reflects not only competition to be regarded as the strongest ally of Israel, but also a sense that projecting toughness on Iran may offer one of the few political openings on foreign policy that Republicans can use to attack President Obama. Republicans assert that he has been weak and too solicitous of the Iranian government, while administration officials believe they have orchestrated an array of sanctions and other efforts that have put great pressure on Iran.

One candidate, Representative Ron Paul of Texas, flatly rejects a pre-emptive strike by American forces, absent “credible evidence” that Iran was planning an imminent attack on the United States, which Mr. Paul says would be highly unlikely. He says that the Iranian threat to the Middle East  has also been overstated and that he favors better relations with that country.

WASHINGTON — Details leaking out about an imminent report by United Nations weapons inspectors suggest they have the strongest evidence yet that Iran has worked in recent years on a kind of sophisticated explosives technology that is primarily used to trigger a nuclear weapon, according to Western officials who have been briefed on the intelligence.

But the case is hardly conclusive. Iran’s restrictions on inspectors have muddied the picture. And however suggestive the evidence about what the International Atomic Energy Agency calls “possible military dimensions” of Iran’s program turns out to be, the only sure bet is that the mix of sleuthing, logic and intuition by nuclear investigators will be endlessly compared with the American intelligence agencies’ huge mistakes in Iraq in 2003.

Just as it was eight years ago, the I.A.E.A., which was conceived as a purely technical organization insulated from politics, is about to be sucked into the political whirlpool about how the world should respond to murky weapons intelligence. Except this time everything is backward: It is the I.A.E.A., which punched holes in the Bush administration’s claims about Iraq’s nuclear progress, that today is escalating the case that Iran has resumed work on bomb-related technology, after years of frustration over questions that have gone unanswered by that government.

A radioactive gas has been detected at Japan's crippled Fukushima nuclear plant, the facility's operator says.

Tepco said xenon had been found in reactor two, which was previously thought to be near a stable shutdown.

There has been no increase in temperature or pressure, but the discovery may indicate a problem with the reactor.

Boric acid - used to suppress nuclear reactions - has been injected as a precaution.

A nuclear reactor in western Japan began starting back up on Tuesday after a month’s hiatus, the first reactor in the country closed for any reason to win approval from a local government to resume operations since the Fukushima nuclear disaster.

United States diplomats have said that the first day of direct talks being held with North Korea in Geneva was useful.

The talks are aimed at restarting negotiations on nuclear disarmament. It is the second such meeting in less than three months.

Chief US negotiator Stephen Bosworth said the talks were moving in a positive direction.

He said the two sides had narrowed some of their differences.

US and North Korean officials are to meet next week in Geneva to try to revive stalled international talks on ending Pyongyang’s nuclear programme.

A state department spokesman in Washington said the talks in Switzerland would be “a continuation of the exploratory meetings”.

The six-party talks broke down in April 2009, just before Pyongyang carried out its second nuclear test.

The US envoy for North Korea is to step down after the Geneva talks.

Right-wing media have been hyping the claim that a diplomatic cable released by WikiLeaks shows that President Obama had planned to "apologize" for the bombing of Hiroshima during his 2009 visit to Japan. But the cable only shows there was speculation from "anti-nuclear groups" that Obama might travel to Hiroshima after expressing support for a "nuclear-free world," and the Obama administration has said no apology was ever planned.

Japanese health workers have begun checking more than 300,000 children living near the Fukushima nuclear plant for thyroid abnormalities.

Parents have expressed concern about a link between thyroid abnormalities and radiation, citing reports of a rise after Chernobyl in 1986.

The Fukushima plant was crippled by the earthquake and tsunami in March which killed 20,000 people.

Concerns remain high over the possible effects of any lingering contamination.

The tests began after an unofficial survey which found that 10 out of 130 children evacuated from Fukushima had hormonal and other irregularities in the thyroid glands, according to AFP news agency.

But those who conducted the survey said they could not establish a link between the irregularities and Japan's nuclear crisis.

TOKYO — Despite continued fears over radiation levels, Japan lifted evacuation advisories for an area spanning five towns and cities around a tsunami-ravaged nuclear power plant on Friday, the first such move since multiple fuel meltdowns at the site led to a substantial radiation leak and forced more than 100,000 surrounding residents to flee.

The easing was a bid by the government to bring the country a step closer to normalcy after the March 11 quake and tsunami, which destroyed wide areas of Japan’s Pacific coast and set off the world’s worst nuclear disaster since Chernobyl. But with lingering fears over radiation levels — as well as slow progress in decontaminating towns and cities hit by radioactive plumes — a return to these areas will likely be slow.

A 12-mile exclusion zone will remain in place around the Fukushima Daiichi Nuclear Power Plant, which the government is working to bring under control. The worst contaminated areas close to the plant are likely to remain uninhabitable for decades, government officials have acknowledged.

Still, the government decided Friday to lift evacuation advisories for five lesser-hit towns and cities just outside that radius. Radiation levels in those towns and cities were stable enough to warrant lifting the advisories, which affected about 59,000 people, officials said. About 30,000 of those people had already returned to the area as radiation fears eased.

Iran announced the mass production of a new cruise missile on Wednesday, the latest in a series of belligerent-sounding proclamations from that country in the face of its increased isolation by a Western-led group of nations worried about Iran’s nuclear program and avowed hostility toward Israel.

Brig. Gen. Ahmad Vahidi, Iran’s defense minister, said the new missile, first unveiled a month ago and known as the Qader, which means Able in Farsi, had been mass-produced “as quickly as possible,” the country’s state-run media reported. The missile, designed to destroy warships and coastal targets, has a range of about 125 miles, the media said.

The announcement coincided with front-page headlines in a number of Iranian newspapers quoting the head of Iran’s navy, Rear Adm. Habibollah Sayyari, as saying he intended to deploy Iranian warships close to the Atlantic coast of the United States to reciprocate for the patrols in the Persian Gulf by the United States Navy’s Fifth Fleet. The patrols are a constant source of irritation to Iran.

“Like the arrogant powers that are present near our marine borders, we will also have a powerful presence close to American marine borders,” the official Islamic Republic News Agency quoted him as saying.

The admiral gave no indication when such deployments might happen or how many ships he intended to dispatch. Nor was there any explanation of how the vessels, thousands of miles from home in unfriendly territory, might refuel or replenish supplies.

Obama administration officials downplayed the Iranian admiral’s remarks. Jay Carney, the White House spokesman, told reporters in Washington that the United States did not take them seriously “given that they do not at all reflect Iran’s naval capabilities.”

In another slap at the United States, General Vahidi also rejected any thought of creating a telephone hotline between Tehran and Washington. The idea that was floated a few weeks ago by Adm. Mike Mullen, the outgoing chairman of the Joint Chiefs of Staff, as a way of avoiding an accidental confrontation in the Persian Gulf, where American and Iranian naval vessels and aircraft sometimes operate within sight of each other.

Admiral Mullen noted that even “in the darkest days of the Cold War” the United States and Soviet Union had such a relationship, and that he worried about the absence of a hot-line connection with Iran.

“We do not need such a line in the region,” General Vahidi said, according to Iran’s Fars News Agency. “They are seeking to set up a hotline in order to solve any potential tensions, whereas we believe if they leave the region, there will be no tension.”

India successfully test-fired a short-range, nuclear-capable missile on Monday, the Defense Ministry said. The Prithvi missile, which has a range of 220 miles, was fired from a testing range in Chandipur in Orissa State and hit a target in the Bay of Bengal with high accuracy, said a Defense Ministry spokesman, N. Ao. India’s missiles are intended primarily for any confrontation with its regional rival, Pakistan. Both nations routinely test missiles and the launching on Monday was unlikely to aggravate tensions.

Government officials on Saturday ordered more tests after detecting elevated levels of radiation in rice crops near the crippled nuclear power plant at Fukushima.

Radioactive substances have already been discovered in beef, milk, spinach and tea leaves, leading to recalls and bans on shipments. But officials have been especially worried about rice, a staple that makes up a significant part of the Japanese diet. Japan grows most of the rice that it consumes.

Preliminary tests on rice from paddies in the city of Nihonmatsu, about 35 miles from the Fukushima plant, showed the crops contained 500 becquerels per kilogram of radioactive cesium, prefectural officials said. Under recently adopted Japanese regulations, rice with up to 500 becquerels per kilogram of radioactive cesium is considered safe for consumption. (A becquerel is a frequently used measure of radiation.)

As a result of the latest findings, officials in Fukushima have ordered further checks on rice from the area, and they may ban shipments if similarly high levels of radiation are found again, prefectural officials told reporters.

Meetings between the chief nuclear envoys of North and South Korea were “constructive,” negotiators said, even though the talks did not produce any breakthroughs on the longstanding impasse over the North’s refusal to give up its nuclear program.

The talks on Wednesday, held at a private club in Beijing, were the second meeting of the two sides since 2009, when North Korea walked away from six-party disarmament talks that also involved the United States, Russia, Japan and China.

Although he did not elaborate on what was discussed, Wi Sung-lac, the South Korean envoy, expressed guarded satisfaction. “We will continue to make these efforts in the future,” he told reporters, according to the Yonhap news agency.

North Korea wants the six-way talks to resume immediately without preconditions. South Korea, backed by the United States, insists that the North suspend its uranium-enrichment program, halt missile testing and allow international inspectors to return before the talks resume.

The South has also demanded that the North acknowledge responsibility for the torpedoing of a South Korean warship and the shelling of an island last year, killing a total of 50 people.

The North angrily abandoned the six-party talks in April 2009 after a United Nations rebuke over its launch of a long-range missile. A month later, it detonated a nuclear device underground, prompting a round of international sanctions that have sapped the North’s already anemic economy.

Although relations between the Koreas have deteriorated since then, experts believe that the North is desperate for food aid and an easing of the sanctions, and thus is eager for talks to resume.

China, the host of the talks and North Korea’s most steadfast ally, said on Wednesday that the North Korean prime minister, Choe Yong-rim, would visit Beijing on Sept. 26.

German industrial and engineering conglomerate Siemens is to withdraw entirely from the nuclear industry.

The move is a response to the Fukushima nuclear disaster in Japan in March, chief executive Peter Loescher said.

He told Spiegel magazine it was the firm's answer to "the clear positioning of German society and politics for a pullout from nuclear energy".

"The chapter for us is closed," he said, announcing that the firm will no longer build nuclear power stations.

A long-planned joint venture with Russian nuclear firm Rosatom will also be cancelled, although Mr Loescher said he would still seek to work with their partner "in other fields".

Siemens was responsible for building all 17 of Germany's existing nuclear power plants.

Iran on Monday made its first counterproposal in two years to ease the confrontation with the West over its nuclear program, offering to allow international inspectors “full supervision” of the country’s nuclear activities for the next five years, but on the condition that the mounting sanctions against Iran are lifted.

The proposal came from Fereydoon Abbasi, the head of Iran’s atomic energy agency, who was designated by the United Nations in 2007 as a scientist involved in Iran’s nuclear and ballistic missile activities, and, as such, subject to a freeze on his assets and limitations on his travel. He narrowly escaped an assassination attempt last year.

Mr. Abbasi’s offer was vaguely worded. It was far from clear what he meant by “full supervision,” after several years in which Iran has refused to turn over documents to the International Atomic Energy Agency or allow interviews of its most important nuclear scientists. The government has also restricted where inspectors could travel.

Nonetheless, the overture is the first time since October 2009 that Iran has indicated a willingness to negotiate over the program, and one senior Obama administration official said the offer suggested “that the sanctions are wearing on the leadership.”

Mr. Abbasi made his statement to the Iranian Student News Agency, which is considered a semiofficial organ and has been used to convey changes of position in the past. “We proposed that the agency keep Iran’s nuclear program and activities under full supervision for five years, provided that sanctions against Iran are lifted,” he told the news agency.

International nuclear inspectors reported on Friday that Iran had finally begun operating a new generation of equipment that over time should give it the capability to produce nuclear fuel much faster, after years of delays made worse by Western sanctions and sabotage.

The equipment, new centrifuges that the inspectors described in a report circulated to members of the International Atomic Energy Agency, is intended to replace balky, breakdown-prone machines whose design Iran first bought from Abdul Qadeer Khan, a Pakistani who illicitly sold production equipment and bomb designs. Five years ago, President Mahmoud Ahmadinejad of Iran declared that the machinery, which he claimed was made in Iran, would soon be deployed. It became clear that his boast was premature.

Iran has ignored four sets of United Nations Security Council resolutions to cease enriching uranium. But it took until this summer for the country to begin using 54 of the new centrifuges, which the Iranians call the IR-2 and claim were produced entirely in its own small factories.

Because the machines spin much faster than the models they are intended to replace, they could speed Iran’s ability to enrich large quantities of nuclear fuel. The Central Intelligence Agency, in its assessments of Iran’s capabilities, has expressed doubts that the machines shown to inspectors would be used for producing weapons-grade material, but they have warned that the installation at the uranium enrichment complex at Natanz might be intended to work out bugs and that Iran could have secret facilities.

The earthquake last Tuesday in Virginia may have produced stronger shaking at the North Anna nuclear plant than the reactors were designed to withstand, and the Nuclear Regulatory Commission has sent additional inspectors to determine what steps are needed to determine if there is damage. No significant damage has been identified so far.

Both reactors shut down automatically because the earthquake, which was centered about 10 miles away, disrupted access to off-site power supplies. Both are now in “cold shutdown,” which means that their fuel is no longer producing much heat and the cooling water temperature is below 212 degrees.

The North Korean leader, Kim Jong-il, has agreed to consider a moratorium on nuclear weapons tests and production, and said he would return to stalled six-party talks on the nation’s nuclear program, the Russian presidential press secretary told the Russian news media on Wednesday.

Mr. Kim made the agreement at a meeting with President Dmitri A. Medvedev in the southern Siberian city of Ulan Ude, where he is stopping on a weeklong trip in his armored train.

“They confirmed their willingness to go back to the negotiations without preconditions,” the press secretary, Natalya Timakova, said after the meeting.

“In the course of the talks, North Korea will be ready to resolve the question of imposing a moratorium on tests and production of nuclear missile weapons,” she was quoted as saying.

Washington and Seoul have demanded that North Korea announce such a moratorium before, not after, six-party talks begin. Still, Mr. Kim’s reported comment offered another sign that his government wanted to return to the nuclear disbarment talks.

A plan to complete work on a US nuclear reactor at a half-built plant in Alabama has been approved, more than 20 years after construction was halted.

The Tennessee Valley Authority approved the $4.9bn (£3bn) plan to restart construction, which stopped in 1988 amid declining power demand estimates.

The Bellefonte Nuclear Plant is expected to be operational by 2020.

One idea, a half-century old, has been to do it with nothing more substantial than lasers and their rays of concentrated light. This futuristic approach has always proved too expensive and difficult for anything but laboratory experimentation.

Until now.

In a little-known effort, General Electric has successfully tested laser enrichment for two years and is seeking federal permission to build a $1 billion plant that would make reactor fuel by the ton.

That might be good news for the nuclear industry. But critics fear that if the work succeeds and the secret gets out, rogue states and terrorists could make bomb fuel in much smaller plants that are difficult to detect.

Iran has already succeeded with laser enrichment in the lab, and nuclear experts worry that G.E.’s accomplishment might inspire Tehran to build a plant easily hidden from the world’s eyes.

Backers of the laser plan call those fears unwarranted and praise the technology as a windfall for a world increasingly leery of fossil fuels that produce greenhouse gases.

But critics want a detailed risk assessment. Recently, they petitioned Washington for a formal evaluation of whether the laser initiative could backfire and speed the global spread of nuclear arms.

Iran's top nuclear negotiator said Tuesday that a Russian proposal "can be a basis to start negotiations" on its disputed nuclear program that have been stalled since January.

Russia's "step-by-step" approach calls for the international community to make limited concessions to Iran for each step it takes toward meeting demands to come clean about its nuclear intentions.

"The proposal by our Russian friends can be a basis to start negotiations for regional and international cooperation, specifically in the field of peaceful nuclear activities," negotiator Saeed Jalili said on Iran's state TV.

"Dialogue for cooperation can be a good strategy," Jalili said.

Jalili made the comments after holding two rounds of talks with Russia's Security Council chief, Nikolai Patrushev in Tehran Tuesday.

How did Germany, Europe’s economic powerhouse, turn its back on nuclear energy?

Most directly, the decision belonged to Chancellor Angela Merkel. Unlike other world leaders, she is a trained scientist, with a Ph.D. in physics.

She reached the momentous decision to phase out nuclear power by 2022 after discussing it one night over red wine with her husband, Joachim Sauer, a physicist and university professor, at their apartment in central Berlin, according to people who spent many hours debating the issue with her but spoke only on the condition that they remain anonymous.

The decision to switch off Germany’s nuclear power plants has been widely portrayed as a sudden U-turn by Mrs. Merkel. After the nuclear disaster in Japan in March, the German public, long opposed to nuclear power, was ready to pull the plug, and their chancellor, known for shifting with the prevailing political winds, complied.

But those close to Mrs. Merkel described her change of heart as something more like an awakening. Powerful industrial and energy interests fought the shift, but Mrs. Merkel, her allies say, is ready to lead Germany into a new era in which wind and solar energy, along with enhanced efficiency, can be developed fast enough to replace the lost power from nuclear plants

Even at this date — on the 66th anniversary of the first use of the atomic bomb against a city — few Americans know that among the tens of thousands victims in Hiroshima were at least a dozen and perhaps more American prisoners of war. This was kept from the American people—even the families of the Americans — for decades, along with so much else related to the atomic bombings (as revealed in my new book).

North Korea must suspend all activities at its nuclear complexes and allow United Nations inspectors to verify a freeze before the six-nation negotiations can resume on economic and other rewards for the country in exchange for ending its nuclear weapons programs, the chief South Korean nuclear negotiator said Friday.

“North Korea should take these presteps to improve six-party talks and make them more effective when they are resumed,” said Wi Sung-lac, who met his North Korean counterpart, Ri Yong-ho, last week in Indonesia, referring to previous rounds of negotiations that included the two nations as well as the United States, Japan, Russia and China. “The North Korean reaction was not positive.”

The United States pressed the same demands during two days of talks with North Korean officials in New York that ended inconclusively on Friday. The meetings between Stephen W. Bosworth, the special American envoy on North Korean affairs, and Kim Kye-gwan, the first vice foreign minister of North Korea, were the first between the two sides since Mr. Bosworth visited North Korea in December 2009.

Three men in charge of nuclear power safety and policy have been sacked amid the ongoing crisis at the tsunami-hit Fukushima Daiichi nuclear plant.

Japan's Trade and Industry Minister, Banri Kaieda, said the three senior officials would be held responsible for mishandling the plant and its problems.

Radioactive material is still leaking from the plant nearly five months on.

The crisis has also brought to light the close links between the government and the power industry.