• Reid said Saturday the plan Collins was assembling was no longer on the table, because it treated reopening the government as a "concession." Reid continues to demand that any plan include a "clean" bill, one that raises the debt limit and reopens the government with no strings attached. However, Manchin's comments Monday indicated the Collins plan remained alive.
• Republicans blocked a measure to extend the debt limit with no strings attached, refusing to support a procedural vote that would have brought it to the Senate floor.
• House Republican leaders said Obama rejected their proposal for a six-week extension of the federal debt ceiling.
• Meanwhile, Republicans objected to the prospect being floated over the weekend that the forced spending cuts of sequestration, which have cut deeply into federal operations since March, might be rolled back under any eventual deal.
The Treasury Department said it will be unable to pay the government's bills unless the debt limit is increased by Thursday.
Christine Lagarde, head of the International Monetary Fund, said Saturday the consequences of a failure to raise the debt limit would be dire for economies around the world. She spoke to CNN's Richard Quest at an Institute of International Finance conference in Washington.
"You know, I've just spent the last two days with representatives of about 188 countries around the world. I wouldn't say they are confident. I would say they are concerned, and they are very anxious to see this crisis resolved, because they know it's going to impact on their economy," Lagarde said.
Obama spoke by phone with House Minority Leader Nancy Pelosi on Sunday to discuss the ongoing battle over the shutdown, the White House said. The two agreed on the need for a "clean debt limit increase" and a "clean continuing resolution to open up the government and end the shutdown."
Mindful that the Thursday deadline is days away, House Republican leaders are considering all their options even as Republican and Democratic Senate leaders try to craft a deal on the debt ceiling, said a GOP leadership aide, speaking on the condition of anonymity.
One option Republican leaders are considering is sending back a measure to the Senate that would increase the debt limit; exactly what it would contain is unknown at this time.
But the aide noted that the House is able to move quicker than the Senate, and this idea could come into play. If a decision were made to pursue this idea, then it would require Democratic support to pass in the House.
Senate Democrats meet with president
Senate Democrats met with Obama on Saturday, and a Senate Democratic leadership aide said the party is unified.
"Democrats are willing to negotiate on anything Republicans want to discuss as soon as we reopen the government and pay our bills," said the aide.
Another Democratic source said party leaders regard Republicans as lacking a coherent position. They hope McConnell can "cut through the clutter," the source told CNN's Dana Bash.
The sources, who are familiar with the talks, spoke on the condition of anonymity so they could speak candidly.
Even as he demanded a "clean" bill, Reid said he and McConnell are involved in "cordial" and "preliminary" discussions.
"I hope that our talking is some solace to the American people and the world," Reid said. He said McConnell had approached him. "This hasn't happened until now."