WASHINGTON- The White House said Monday that President Barack Obama regrets his vote as a senator in 2006 against raising the debt limit - a vote he's now pressuring Congress to take.

Obama "thinks it was a mistake," presidential spokesman Jay Carney told reporters. "He realizes now that raising the debt ceiling is so important to the health of this economy and the global economy that it is not a vote that, even when you are protesting an administration's policies, you can play around with."

The country will reach its debt limit of $14.3 trillion by May 16. If Congress doesn't raise it by then or shortly thereafter, the government would not be able to make debt payments, leading to an unprecedented default of the national debt and driving up borrowing costs for the government, U.S. companies and consumers, the Treasury Department warns.

Republicans who control the House are threatening to withhold their votes to increase the debt ceiling unless Obama agrees to major spending cuts. The White House is insistent that the debt ceiling be extended without any attempts to cut spending attached to it.

That means Washington is right back where it started before the budget fight that nearly resulted in a government shutdown last week. Both sides show no give even though they'll have to compromise in order to avoid an outcome everyone says they want to avoid.

With the stakes higher this time, the clash over the debt limit that looks likely to consume Washington in coming weeks could far overshadow the budget showdown that ended in a last-minute deal Friday night.

The White House's explanation Monday of Obama's changed position on the debt limit was an attempt to prepare for the fight by inoculating the president against charges of flip-flopping already being leveled by Republicans.

Congress is forced to increase the debt limit every several years and it often turns political with members of the minority party withholding their votes to extract concessions or direct criticism at the party that controls the White House.

That was the case in 2006 when Republican George W. Bush was president and Obama, a freshman senator from Illinois, declared on the Senate floor: "The fact that we are here today to debate raising America's debt limit is a sign of leadership failure. ... Increasing America's debt weakens us domestically and internationally. Leadership means that 'the buck stops here.' Instead, Washington is shifting the burden of bad choices today onto the backs of our children and grandchildren. America has a debt problem."

Today similar arguments are heard from Republicans.

"The president has asked us to increase the debt limit, in other words to increase the limit on the credit card, without doing anything about the source of the problem. And we've got to deal with the source of the problem," House Speaker John Boehner, R-Ohio, said Monday on Fox News Channel.

"My members won't vote to increase the debt limit unless we're taking serious steps in the right direction," Boehner said.

Carney didn't disavow Obama's comments from 2006. But he said the president understands now that "when you're in the legislature, when you're in the Senate, you want to make clear your position if you don't agree with the policies of the administration."

"But there are many other ways to do it," he said. "We do not need to play chicken with our economy by linking the raising of the debt ceiling to anything."

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