The White House meeting in the afternoon was to include the top Republican leaders, Senate Majority Leader Mitch McConnell and House Speaker Paul Ryan .

"Given that the President doesn't see a deal between Democrats and the White House, we believe the best path forward is to continue negotiating with our Republican counterparts in Congress instead," Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi said in a joint statement. "Rather than going to the White House for a show meeting that won't result in an agreement, we've asked Leader McConnell and Speaker Ryan to meet this afternoon."

Congress' top two Democrats canceled plans Tuesday to attend an Oval Office meeting after President Donald Trump tweeted that he could not envision a fiscal deal to avoid a government shutdown.

In response to the cancellation, Ryan and McConnell issued a joint statement accusing the Democratic leaders of "antics" and finding "new excuses not to meet with the administration to discuss these issues."

White House Press Secretary Sarah Huckabee Sanders said the invitation "still stands, and [Trump] encourages them to put aside their pettiness, stop the political grandstanding, show up and get to work."

Trump's tweet raised the prospect of a potentially disastrous government shutdown.

Meeting with "Chuck and Nancy" today about keeping government open and working. Problem is they want illegal immigrants flooding into our Country unchecked, are weak on Crime and want to substantially RAISE Taxes. I don't see a deal!

The purpose of the meeting was to begin urgent negotiations to pass a federal budget and spending plan before the government runs out of funding on Dec. 8. Republicans are insisting that as part of any deal, caps on military spending be lifted. Democrats are expected to use their leverage to demand policy protections for the so-called immigration Dreamers and a reauthorization of the Children's Health Insurance Program.

The trouble with Trump's inability to see "a deal" is that Republicans cannot pass a federal spending bill without Democratic votes in the Senate, where a 60-vote majority will be needed to move the bill forward. In the House, Republicans have needed Democratic votes in recent years to pass spending bills, because the GOP caucus' most conservative members have refused to support the bills.

This gives Democrats far greater leverage in these negotiations than they have on tax reform, for instance, where Republicans can pass a bill with a simple majority in the Senate and near-unanimous support from House Republicans.

Even if a deal is reached at the 11th hour, the prospect of a government shutdown could rattle financial markets. In the event that a shutdown were to occur, the results would likely be disastrous for Republicans heading into the 2018 midterm elections.

The last shutdown, in October 2013, lasted 16 days and cost the economy more than $1 billion a day, according to most estimates.