The House of Representatives won't vote on any plans to avert the "fiscal cliff" on Monday, leaders have told members.
Earlier Monday, President Barack Obama had said an agreement to avert the automatic tax increases and spending cuts appeared to be "within sight."
The deal would prevent a tax increase for the overwhelming majority of Americans, extend the child tax and tuition credits for families as well as those for clean-energy companies and extend unemployment benefits for two million people, Obama said.
But the country will technically go over the cliff at midnight Monday if the House also doesn't pass such a deal.
Obama said he expected to remain at the White House for New Year's Eve while lawmakers used up every last second available to them.
"Keep the pressure on over the next 12 hours or so," he urged supporters. "Let's see if we can get this thing done."
A GOP source told CNN negotiators are "very close" to a deal. The sticking point is $24 billion in spending cuts being sought by Republicans in place of deeper cuts that would automatically take effect at midnight, according to the source.