President Obama summoned congressional leaders to a Friday summit at the White House in a last-ditch effort to protect taxpayers, unemployed workers and the fragile U.S. recovery from severe austerity measures set to hit in just four days.

The meeting comes less than 48 hours after Obama reached out to top Republicans by telephone from his Christmas vacation in Hawaii in hopes of reviving efforts to avert the so-called "fiscal cliff", which stalled when the House abruptly left town late last week.

Hours later, House Speaker John A. Boehner (R-Ohio) announced that he would call the House back into session this weekend. And in perhaps the most significant development, Senate Minority Leader Mitch McConnell (R-Ky.) for the first time was engaged directly in talks with the White House. He signaled an interest in cutting a deal.

“The truth is, we’re coming up against a hard deadline here ... And Republicans aren’t about to write a blank check for anything Senate Democrats put forward just because we find ourselves at the edge of the cliff,” McConnell said in a speech Thursday afternoon on the Senate floor.

“We’ll see what the president has to propose,” McConnell said. “Hopefully, there is still time for an agreement of some kind that saves the taxpayers from a wholly preventable economic crisis.”

Boehner spokesman Brendan Buck said the speaker "will continue to stress that the House has already passed legislation to avert the entire fiscal cliff, and now the Senate must act."

Aides from both parties expressed hope that legislation could be pushed through Congress before the New Year’s Eve deadline, but they cautioned that quick action would require leaders in both chambers to quickly rally around a set of specific policies.