WASHINGTON - US President Barack Obama refused Friday to negotiate with Republicans over raising the debt ceiling and declared he does not think they would be “crazy enough” to revisit such a tactic.

Top Republicans have said they will not increase US borrowing authority without extracting spending cuts from the administration, raising the specter of a new bruising fiscal battle in the coming months just as Congress managed to come together in December and finally pass a budget agreement.

But Obama, who has endured several fights over US borrowing authority in recent years, including one that shut down the government for 16 days in October, appeared eager to head off such a confrontation. “I can’t imagine that, having seen this possible daylight breaking when it comes to cooperation in Congress, that folks are thinking about plunging us back into the kinds of brinksmanship and governance by crisis that has done us so much harm over the last couple of years,” Obama said during a White House press conference. “To repeat: the debt ceiling is raised simply to pay bills that we have already accrued. It is not something that is a negotiating tool, it’s not leverage,” Obama said. “It’s the responsibility of Congress. It’s part of doing their job, (and) I expect them to do their job.”

House Budget Chairman Paul Ryan, a lead author of the budget deal that passed Congress this week, set the debt ceiling discussion rolling on Sunday when he described the upcoming borrowing authority issue in confrontational terms.

“We don’t want nothing out of this debt limit. We’re going to decide what it is we can accomplish out of this debt-limit fight,” he told Fox News Sunday. Obama, who praised Ryan for crafting the budget agreement, said he hoped to “have a constructive conversation of the sort that we just had in resolving the budget issues. But as for revisiting a fight over the debt ceiling, “I’ve got to assume folks aren’t crazy enough to start that thing all over again,” the president said.

The US debt currently stands at $17.2 trillion. After a bruising legislative battle, Congress in October extended the debt ceiling through February 7, amid fears the world’s largest economy could default on its debt.On Thursday, Treasury Secretary Jacob Lew wrote lawmakers warning that the United States will run out of money to pay its bills by early March if Congress does not raise the debt ceiling again.