Debt limit has to go up: President Obama

President Barack Obama Monday rejected any negotiation with Republicans over the most pressing fiscal issue, refusing to trade cuts in government spending in exchange for raising the borrowing limit.

"If the goal is to make sure that we are being responsible about our debt and our deficit - if that's the conversation we're having, I'm happy to have that conversation," Obama said at a news conference. "What I will not do is to have that negotiation with a gun at the head of the American people."

Republican leaders quickly reiterated their demand that increasing the debt limit must be accompanied by spending cuts.

With an agreement to prevent the so-called "fiscal cliff" of sharp spending cuts and tax increases barely two weeks old, the president faces another fiscal showdown with congressional Republicans.

A trio of deadlines looms around the end of February: the need to raise the debt ceiling, automatic deep spending cuts temporarily put off in the "fiscal cliff" deal and the end of a stopgap government funding measure.

The U.S. could default on its debt if the borrowing limit is not increased.

Also Monday, Obama said he would formally present this week a list of "sensible, common-sense steps" to reduce gun violence from Vice President Joe Biden, and vowed to work vigorously to implement them.

Though the proposals have not been made public, a rough outline of what the president hopes to pursue is clear. Obama reiterated that he would support reinstating a ban on assault weapons, stricter controls on high-capacity ammunition clips and stronger background checks.

Biden has had a series of meetings with officials in the weapons and entertainment industries as part of a task force requested by the president after last month's Sandy Hook shooting.