The White House abruptly postponed a meeting with congressional leaders set for Monday afternoon, amid signs that senators were working on a new proposal to address the partial government shutdown and the looming debt-ceiling deadline. 

The White House said in a statement that it was postponing the meeting to give senators more time to build on "important progress." 

The announcement was preceded by a new round of talks between Senate Majority Leader Harry Reid and Senate GOP Leader Mitch McConnell. 

Asked if they were closer to a deal, Reid said: "I hope so." A McConnell spokesman said the two were "engaged in good faith negotiations and those talks will continue." 

Both leaders later said on the Senate floor that they were "optimistic."

The emerging framework, according to Senate sources, would encompass a short-term spending bill and a longer-term increase in the debt ceiling. 

This was described to Fox News as the "reverse" of a bipartisan plan, which included a longer-term spending bill and short-term hike in the debt ceiling, that fizzled over the weekend. 

The new framework would raise the debt ceiling until the spring or summer, and provide funding for the government into January. 

Some health care provisions are also on the table, including the possible repeal of the ObamaCare medical device tax. Asked if senators would "present" this idea to the president, one senior aide said "the president already knows." 

The new framework appears to be driven largely by Senate Democrats, but potentially with buy-in from McConnell. 

The talks come at the start of a critical week for resolving the budget and debt-ceiling impasse. Congress, aside from grappling with the partial government shutdown, faces an Oct. 17 deadline to raise the debt ceiling. After that date, the Treasury Department warns, the U.S. government will not be able to pay all its bills. 

Pressure is mounting from all sides. There is fear that the financial markets could start to dive if traders lose confidence that a deal will ultimately emerge. And furloughed federal workers, now entering week three of the partial shutdown, are just now starting to see the hit to their paychecks. 

But both sides of the debate were having a difficult time keeping track of what the other wants out of a deal. A standoff that began as a fight by Republicans to unravel ObamaCare is now a fight over spending levels -- which has emerged as the single biggest sticking point. 

After a string of budget proposals fell apart over the weekend, GOP lawmakers on Sunday pointedly accused Democrats of trying to squeeze Republicans to roll back across-the-board spending cuts known as sequester. 

"I agree that Republicans started with the overreach, but now Democrats are one tick too cute," Sen. Bob Corker, R-Tenn., told "Fox News Sunday." "They are now overreaching." 

He said "both sides need to come to the middle of the road." 

The prior plan, fronted by Sen. Susan Collins, R-Maine, would have funded the government for six months, raised the debt limit through Jan. 31, and delayed the health care law's medical device tax. 

As Reid dismissed the plan on Saturday, the dispute over spending levels escalated. 

Republicans want to continue current spending at $986.7 billion and leave untouched the new round of cuts on Jan. 15 that would reduce the amount to $967 billion. 

Democrats, though, want to figure out a way to undo the reductions, plus enact a long-term extension of the debt limit increase and a short-term spending bill to reopen the government. 

Republicans bristled at Democrats' demands. A House Republican leadership aide said Sunday that Reid "moved the goalposts" by trying to "violate" spending levels set in the 2011 Budget Control Act. 

"It's time for Democrat leaders to take `yes' for an answer," Senate Republican Leader Mitch McConnell said in a statement. 

But Democrats denied they were trying to violate those levels. 

A Senate Democratic leadership aide said "the suggestion that Democrats insist on breaking the budget caps is false and belied by the facts." 

Essentially, Democrats argue that they would accept current spending levels for a short period -- just not as long as Collins proposed -- so they can have another go at the sequester cuts in the near future. 

Congressional sources confirmed to Fox News that the talks between Reid and McConnell are focusing on the length of the spending bill versus the length of the debt-ceiling increase. Reid wants a longer extension on the debt ceiling, but a shorter-term spending bill. 

Unclear was whether any Senate deal would pass the Republican-controlled House by Thursday, though Senate Democrats were hoping  momentum and the debt-ceiling deadline would pressure House lawmakers. 

Fox News' Chad Pergram and Mike Emanuel and The Associated Press contributed to this report.