By Richard Cowan and David Lawder
WASHINGTON (Reuters) - President Barack Obama and House of Representatives Speaker John Boehner spoke by phone on Tuesday after exchanging new proposals to avert the "fiscal cliff" as negotiations intensified ahead of the end-of-year deadline.
The conversation and exchange of counteroffers over the last two days are the latest sign of possible progress in efforts to avert the automatic steep tax hikes and spending cuts set for January 1 unless Congress intervenes.
White House and congressional aides confirmed that Obama sent Boehner a revised offer in the talks on Monday, and Boehner responded with a counterproposal on Tuesday. But neither side offered any details.
After getting the new offer, Boehner took to the House floor on Tuesday to urge Obama to give more details on the spending cuts the White House would accept in any final deal.
"We're still waiting for the White House to identify what spending cuts the president is willing to make as part of the balanced approach that he promised the American people," Boehner said.
The White House fired back that the administration had submitted extensive proposals to reduce spending but Republicans had not offered specifics on increasing revenues.
"There is a deal out there that's possible," White House spokesman Jay Carney told reporters. It could include reduced spending, more revenues and tax reform as long as Republicans accepted higher tax rates on the wealthiest Americans, he said.
"We do believe the parameters of a compromise are pretty clear," Carney said.
Obama and Boehner have each proposed cutting deficits by more than $4 trillion over the next 10 years, but they differ on how to get there. Economists have warned that failure to strike a deal could send the economy back into a recession.
Obama and Democrats demand that tax rates rise for the wealthiest 2 percent of Americans. Republicans want existing lower rates continued for all brackets and prefer to raise more revenue by eliminating tax loopholes and reducing deductions.
Republicans also want deeper spending cuts than those sought by Obama and fellow Democrats, particularly on social entitlement programs like the government-funded Medicare and Medicaid healthcare plans.
"I'm an optimist. I'm hopeful we can reach an agreement," Boehner said during his speech on the House floor.
But Senate Democratic leader Harry Reid said it would be difficult to reach an agreement before Christmas.
"Until we hear something from Republicans, there's nothing to draft," Reid told reporters, referring to writing legislation based on a deal. "It's going to be extremely difficult to get it done before Christmas."
Boehner spokesman Michael Steel said the counteroffer from Boehner would achieve tax and entitlement reforms that would solve the looming debt crisis, but he offered no more details.
(Additional reporting by Rachelle Younglai, Kim Dixon, Steve Holland and Matt Spetalnick; Writing by John Whitesides; Editing by Alistair Bell and Eric Beech)