US President Barack Obama will host top congressional leaders including his bitter Republican rivals on Friday in a last-ditch bid to halt America's slide over the so-called "fiscal cliff."
A White House official said he will meet his Republican foes House Speaker John Boehner and Senate Minority Leader Mitch McConnell and Democratic allies Senate Majority Leader Harry Reid and House Minority Leader Nancy Pelosi.
McConnell and Boehner's office also confirmed the meeting, which comes amid heightened political tensions and mounting pessimism in Washington over whether a convincing deal can be struck before a year-end deadline.
"We'll see what the president has to propose. Members on both sides of the aisle will review it, and then we'll decide how best to proceed," McConnell said on the Senate floor.
"Hopefully there is still time for an agreement of some kind that saves the taxpayers from a wholly preventable economic crisis."
Senate rivals Reid and McConnell spent Thursday's public appearances blaming one another for the looming failure, with Reid warning that the US economy was more likely than not heading into 2013 without a deal on the books.
"I have to be very honest," Reid said on the Senate floor during a rare holiday week session. "I don't know time-wise how it can happen now."
On Wednesday, the president called the congressional quartet -- McConnell, Reid, Boehner and Pelosi -- hoping to inch forward on a deal, but lawmakers and their aides have stressed there was little to no progress over the holidays.
Obama cut short his Christmas vacation in Hawaii to return to the White House, where he ignored reporters' shouted questions about the crisis, four days before a deadline to agree a deal on tax and spending.
He came back to a sharply divided Washington, where the mood has soured on a possible plan to prevent hundreds of billions of dollars in tax hikes and deep automatic spending cuts from kicking in from January 1.
McConnell told the Senate he was "happy" to look at any Obama proposal, warning: "But the truth is we're coming up against a hard deadline here."
The lawmaker insisted the Senate Democratic majority had yet to offer a viable solution and that if they did "members on both sides of the aisle will review it, and then we'll decide how best to proceed.
Despite reports from some quarters that Obama had drawn up his own plan to offer lawmakers, there was no sign that the White House was ready to intervene.
Lawmakers have refused to compromise and Reid blamed Republicans for the breakdown.
Reid said Boehner was running a "dictatorship" in the House by refusing to put to a vote a Senate-passed bill which would prevent taxes from rising on all households making less than $250,000 per year.
He also took Boehner to task for keeping his members on vacation while the Senate was hard at work.
Without McConnell and Boehner "nothing can happen on the fiscal cliff -- and so far they are radio silent," Reid said, urging them to "put the economic fate of the nation ahead of your own fate as speaker of the House."
Boehner's office shot back with a curt message.
"Senator Reid should talk less and legislate more," Boehner spokesman Michael Steel said, arguing the House has passed bills that would extend tax breaks for all Americans and replace the indiscriminate spending cuts.
"Senate Democrats have not," he added.
House leaders eventually ordered members to return for a session on Sunday, warning that the House "may be in session through Wednesday, January 2."
A new Congress convenes on January 3.
The deadlock has spooked markets, left Americans wondering whether they will pay thousands more in taxes next year, and worried the Pentagon, which fears defense cuts could undermine the military.
Complicating efforts to avoid disaster, Treasury Secretary Timothy Geithner has warned the nation will reach its $16.39 trillion debt limit on December 31 and his department take "extraordinary measures" to avoid a US default.
Experts say a failure to strike a cliff compromise by New Year's Eve could plunge the world's biggest economy into recession, and wrangling over the debt ceiling will only exacerbate fiscal uncertainty.