“The practical implications of this is bankruptcy for the United States,” Gregg said of the Obama’s administration’s recently released budget blueprint. “There’s no other way around it. If we maintain the proposals that are in this budget over the ten-year period that this budget covers, this country will go bankrupt. People will not buy our debt, our dollar will become devalued. It is a very severe situation.”

Gregg, known as one of the keenest fiscal minds on Capitol Hill, also told CNN Chief National Correspondent John King that he thought it was “almost unconscionable” for the White House to continue with its planned course on fiscal matters with unprecedented actual and projected budget deficits in the coming years.

“It is as if you were flying an airplane and the gas light came on and it said ‘you 15 minutes of gas left’ and the pilot said ‘we’re not going to worry about that, we’re going to fly for another two hours.’ Well, the plane crashes and our country will crash and we’ll pass on to our kids a country that’s not affordable.”

Despite his criticism of Obama’s approach to the long-term finances of the country, Gregg praised how Obama’s top economic lieutenants are trying to get the sick banking system back to health.

“They’re doing the right things,” Gregg said about embattled Treasury Secretary Timothy Geithner and White House economic adviser Larry Summers. “They haven’t done it as definitely as they should have . . . but they are moving in the right direction and the Fed is moving in the right direction,” Gregg said on CNN’s State of the Union.

Gregg broke ranks with some of his fellow Republicans and said he did not think Geithner should step down from his Cabinet post.

On the recent scandal of more than $150 million in bonuses paid to the AIG employees whose work pushed the financial giant to the brink of collapse, Gregg criticized the plan afoot on Capitol Hill to tax those bonuses at very high rates. But, Gregg pointed out that the Obama administration and, to some extent, the Bush administration before it failed to “discipline” the bonuses paid out by AIG, which is now 80 percent owned by the federal government.

The Republican senator was appointed to be Obama’s Commerce Secretary but then bowed out unexpectedly, citing policy differences with the Democratic administration.