President Obama on Monday called out "professional politicians" who have argued against raising the nation's debt limit, a shot across the bow at some of the Republicans vying to challenge him in 2012. 

Obama, in a late-morning news conference meant to pressure GOP leaders on Capitol Hill in negotiations over the debt limit, dismissed as "irresponsible" the notion that the nation couldn't authorize more borrowing.

"I will say that some of the professional politicians know better," Obama said. "And for them to say that we shouldn't be raising the debt ceiling is irresponsible. They know better."

The president didn't name any names, though his comments are a sure reference to some of the candidates running to replace him as president, and to some congressional Republicans who have questioned the need for raising the debt limit.

Rep. Michele BachmannMichele Marie BachmannBachmann won't run for Franken's Senate seat because she did not hear a 'call from God' Billboard from ‘God’ tells Michele Bachmann not to run for Senate Pawlenty opts out of Senate run in Minnesota MORE (R-Minn.) refused, emphatically, in her first TV ad airing in Iowa, to vote in favor of raising the debt limit.

"I. Will. Not. Vote. To increase the debt ceiling," she says at the end of the ad.

Former Minnesota Gov. Tim Pawlenty (R) has also said repeatedly that the Congress shouldn't raise the debt limit, and has urged GOP lawmakers to stand strong against authorizing such a move. He left some wiggle room on Sunday on "Meet the Press," though.

"What I'm willing to do is tell the president of the United States that if he wants the debt ceiling raised, then he should do those things I described earlier," he said, including balancing the budget and capping spending to a set percentage of gross domestic product.

Rep. Ron Paul (R-Texas) has also said he opposes raising the debt limit.

Obama said that neither he nor members of his administration were looking to trump up fears of the debt limit for political maneuvering.

"We're not out here trying to use this as a means of doing all these really tough political things," he said. "Unfortunately, this is what's on our plate. It's before us right now. And we've got to deal with it."