The Republican co-chair of a committee in charge of slashing the nation's deficit on Sunday called deliberations a "roller-coaster ride" and gave no indication that a deal could be struck before the panel's Thanksgiving deadline.
Texas Rep. Jeb Hensarling said the panel will fail unless Democrats agree to significant "structural" changes to entitlement programs like Medicare and Social Security. When asked whether that could be done in a matter of days, he said "we haven't given up hope."
"But if this were easy, the president of the United States (Barack Obama) and the speaker of the House (John Boehner) would have gotten it done themselves," Hensarling said.
Still, Sen. Pat Toomey, R-Pa., a member of the committee, said the two sides are working to bridge differences.
"It's at a difficult point. I think we've got a ways to go," he said. "But I hope we can close that gap very quickly."
Democratic Rep. James Clyburn of South Carolina, another member, also said he hasn't given up.
"All of the ingredients for a good resolution are there," he said. "We just need to develop a will."
The supercommittee has until Nov. 23 to agree on how to reduce the deficit by at least $1.2 trillion in the next decade. Any amount less than that would be made up in automatic across-the-board cuts divided evenly between defense and domestic programs.
The panel has been stymied for weeks over taxes. Democrats want to raise revenue by making tax code changes that directly add money to government coffers. Republicans have agreed to increase government revenue, but are demanding large cuts to benefit programs, which they say are bleeding Americans dry.
Each side has blamed the other for failing to move forward. Last week, White House Press Secretary Jay Carney said that Obama has told panel members that their finished product must contain both sources of new revenue, or taxes, as well as spending cuts.
Hensarling offered no new talking points Sunday, indicating that the two sides likely remain far from reaching consensus.
"We want more revenues," he said. "We just want to raise it by growing the economy."
Virginia Sen. Mark Warner, a Democrat who supports entitlement and tax reform, suggested that politics was the biggest culprit in preventing a deal.
"You'll know this supercommittee is getting close when folks on both ends of the political extreme scream the loudest, because that will show that there's actually movement being made," he said.
Sen. Tom Coburn, R-Okla., agreed.
"We can fix our problems but we require leadership from the president, and the leaders from the House and the Senate to say, 'We're going to do this.' And we have not seen that on both sides of the aisle and that's disappointing," he said.
Coburn, a vocal opponent of any tax increase, said he could stand the idea of increasing government revenues if the money comes from restructuring entitlement programs.
"I want to tell you, we're going to touch Medicare because there's nowhere we can borrow the money five years from now to run Medicare the way it is today," he said. "The question really is, will politicians do what is best for the country or best for their party and position?"
Toomey and Clyburn appeared on Fox News Sunday; Hensarling, Warner and Coburn spoke on CNN's State of the Union.
NPR's Tamara Keith contributed to this report, which includes material from The Associated Press