The US is only a few years away from reaching the same debt levels that pushed Greece to the brink of ruin, former comptroller general and head of the Comeback America Initiative David Walker said.

As the ratio of its debt to gross national product eclipsed 100 percent and surged toward 150 percent, Greece has twice in the last two years nearly defaulted on its debt. Only successive bailout packages from the European Union and International Monetary Fund prevented catastrophe.

When tolling up all the US debts, including huge unfunded liabilities to Social Security and Medicare, the US is on dangerous ground, Walker said in a CNBC interview.

"We are less than three years away from where Greece had its debt crisis as to where they were from debt to GDP," he said.

Rep. Michele Bachmann (R-Minn.). who is seeking the Republican presidential nomination, said today on Laura Ingraham's radio show that the debt-limit deal struck by President Barack Obama and congressional leaders is “like saying we embrace being Greece.”

Bachmann preferred the bill she co-sponsored with Reps. Steve King (R-Iowa) and Louie Gohmert (R-Texas) that would pay the interest on the debt, cut checks for military personnel and then prioritize federal spending.

“My opinion is we’re going to now give the president almost a trillion dollars and then come Christmas time, he’ll get potentially--we’ll find it what the final numbers were--potentially upwards of another, in excess of a trillion, maybe as high as another $1.8 trillion but that’s on top of the other $2.2 trillion spending that we do,” Bachmann said.

France and Germany have reached a joint agreement over a Greek bailout package, according to a report in the Financial Times newspaper. Euro-zone leaders will meet later Thursday to try to hammer out a decisive response to the region's sovereign-debt woes. The euro advanced to $1.4266 in early Asian trading hours on Thursday, from $1.4230 in late North American trading on Wednesday.

Greece's lawmakers approved a key austerity bill Wednesday needed to avert default next month, despite a second day of rioting on the streets of Athens that left dozens of police and protesters injured.

The passage of the bill was a decisive step for the country to get the next batch of bailout loans from international creditors and was met with a huge sigh of relief in markets and by Greece's partners in the eurozone. A Greek default could potentially trigger a banking crisis, particularly in Europe, and turmoil in global markets.

Another bill has to be passed Thursday for the government to secure the money.

The bill to cut spending and raise taxes by euro28 billion ($40 billion) over five years, and raise euro50 billion ($71 billion) in privatizations over the same period of time, has provoked widespread outrage, coming after a year of deep cuts that have seen public sector salaries and pensions cut and unemployment rise to above 16 percent.

Greece's prime minister offered to quit and make way for a national unity government after mass protests against a new austerity plan turned violent on Wednesday, with the country teetering on the brink of default.

Senior government sources said Socialist Prime Minister George Papandreou told the leader of the conservative opposition he would be willing to step aside if a unity cabinet agreed on a clear plan to meet the terms of an IMF/EU bailout.

"Prime Minister Papandreou talked with Mr (Antonis) Samaras today and proposed that if the two agreed on a framework of specific commitments for change in the country and the political system and specific targets, he would be willing to stand down from his office," one government source said.

When adding in all of the money owed to cover future liabilities in entitlement programs the US is actually in worse financial shape than Greece and other debt-laden European countries, Pimco's Bill Gross told CNBC Monday.

Much of the public focus is on the nation's public debt, which is $14.3 trillion. But that doesn't include money guaranteed for Medicare, Medicaid and Social Security, which comes to close to $50 trillion, according to government figures.

The government also is on the hook for other debts such as the programs related to the bailout of the financial system following the crisis of 2008 and 2009, government figures show.