Senator Bob Corker told CNBC on Tuesday that he does not think a deal to avoid the "fiscal cliff" will be reached by the end of this week.
The Tennessee Republican said in an interview on CNBC's "Squawk Box" that he's really surprised by the media's optimism over President Barack Obama's new offer to House Speaker John Boehner, which features concessions on revenue.
"We are not close to a deal," Corker said. "I've been trying for three weeks — standing on my head, doing cartwheels — to try to pivot to entitlement reform. This is not a deal here." (Read More: Boehner Proposing a "Plan B" Option)
A source familiar with the negotiations told CNBC the president's new proposal on Monday included lowering his revenue target again to $1.2 trillion, and moving up his threshold for tax hikes on the rich to households making over $400,000. Until now, Obama had insisted on raising taxes on those making $250,000 and above. Boehner said he's willing to go to a million dollars. (Read More: Obama Moves Goal Posts 'Out of the Ballpark,' says Lindsey)
Obama's new offer did detail some spending cuts and saving projections. But Corker characterized them as "nebulous," insisting that any deal needs to include a trillion dollars in entitlement reforms.
Senator Kent Conrad, a Democrat from North Dakota, disagrees. In a separate "Squawk Box" interview on Tuesday, he said the president's plan offers real spending restraint. If it's $400 billion on health care, that's real. If it's $200 billion on some other mandatory spending, frankly that's real."
Conrad said he would like to see more on the spending side, but he thinks fiscal cliff talks are moving in the right direction with Obama and Boehner close to an agreement.
—By CNBC's Matthew J. Belvedere; Follow him on Twitter @Matt_SquawkCNBC