President Obama in the last press conference of his first term drew a hard line over the federal debt ceiling, saying he would not negotiate with Republicans on increasing the nation’s borrowing capacity and insisting Monday that failure to do so would delay Social Security benefits and veterans’ checks.

“While I’m willing to compromise and find common ground over how to reduce our deficit, America cannot afford another debate with this Congress over how to pay the bills they’ve already racked up,” Obama said at a White House press conference. “To even entertain the idea of this happening, of America not paying its bills, is irresponsible. It’s absurd.”

The president attempted to frame his accomplishments of the last four years in a positive light. But the press conference served as an opening salvo to congressional Republicans, who remain insistent that any increase in the debt ceiling must be matched by spending cuts.

“They will not collect a ransom in exchange for not crashing the American economy,” Obama said. “The full faith and credit of the United States of America is not a bargaining chip.”

The White House and Congress are looking to reach a deal by late February but remain far apart on the best path forward. And House Republicans were quick to paint the president as aloof to the dangers of a ballooning $16.4 trillion national deficit.

“The American people do not support raising the debt ceiling without reducing government spending at the same time,” House Speaker John Boehner, R-Ohio, said. “The consequences of failing to increase the debt ceiling are real, but so too are the consequences of allowing our spending problem to go unresolved. Without meaningful action, the debt will continue to act as an anchor on our economy, costing American jobs and endangering our children’s future.

After the press conference, Boehner’s office also highlighted Obama’s vote against raising the debt ceiling while a junior senator from Illinois.

Despite repeated questioning from reporters, the president said he had no “Plan B” if Congress does not endorse his plan. Instead the president focused on the potential calamity of not doing so, saying that the U.S. economy could enter another recession.

Once the debt-ceiling debate concludes, Obama said he was open to making modest adjustments to programs like Medicare to protect them for future generations” — but that he also wanted to close tax deductions and loopholes for corporations.

The president in coming days is also looking to outline the administration’s approach to stemming gun violence. Obama said he would review proposals being gathered by Vice President Biden on Monday before unveiling a package of ideas later this week.

“Those of us who look at this problem have repeatedly said that responsible gun owners — people who have a gun for protection, for hunting, for sportsmanship — they don’t have anything to worry about,” Obama said in response to a question about a spike in gun purchases after the Newtown, Conn. massacre.

The president reiterated his support of an assault weapons ban, more extensive background checks for purchases of firearms and news restrictions on high-capacity clips. However, he wasn’t bullish about the proposals making it through the Republican-controlled House.

“Will all of them get through this Congress?” he said. “I don’t know.”