Senate Majority Leader Mitch McConnell on Tuesday delayed the vote on his ObamaCare overhaul plan amid dwindling support from rank-and-file Republicans, touching off what is sure to be a furious scramble to revise the bill and win over GOP holdouts.

"We're going to continue the discussion," the Kentucky Republican said after emerging from a closed-door meeting with Republicans. "We will not be on the bill this week."

President Trump, meanwhile, invited all 52 GOP senators to a White House meeting Tuesday afternoon in hopes of determining the way forward.

"I think the Senate bill is going to be great," Trump said at the start of the East Room meeting, while acknowledging more work to be done. “I think we have a chance to do something very, very important.”

McConnell emerged from the meeting to say the senators, Trump and Vice President Pence “made good progress” but acknowledged that a vote is at least “a couple of weeks” away.

He also said much of the senators’ concerns to the president focused on insurance market reform and the future of Medicaid, whose future growth is curbed by the Senate bill.

“I think we have a very good chance of getting there,” McConnell also said. “The status quo is simply unsustainable.”

Still, the delay is another setback for Washington Republicans, considering all of them including Trump campaigned on a promise to repeal and replace the former President Barack Obama’s signature 2010 health care law.

GOP leaders had wanted to bring the bill to the floor before lawmakers head back to their districts for the break.

This spring, House Speaker Paul Ryan, R-Wis., also had to delay a final vote on his chamber’s overhaul bill upon realizing he didn’t have the votes. It eventually passed.

McConnell needs at least 50 of his senators to vote in favor of the bill. But his problems began almost immediately after he introduced the bill late last week when five of them publicly said they could not support the measure.

Support further dwindled Monday after a financial analysis by the nonpartisan Congressional Budget Office projected that 22 million more Americans would be uninsured by 2026 if the measure replaces ObamaCare.

McConnell apparently delayed the vote upon realizing he didn’t even have votes to even start debate on the measure.

At least five GOP senators -- Susan Collins of Maine, Dean Heller of Nevada, Mike Lee of Utah, Ron Johnson of Wisconsin and Rand Paul of Kentucky -- indicated after the CBO analysis that they wouldn’t vote in favor of starting debate. More came out against the bill after the delay was announced.

Collins this past weekend expressed concerns about the bill curbing Medicaid and cutting Planned Parenthood funding.

McConnell and other GOP congressional leaders pointed to bright spots in the CBO analysis -- including the bill in the coming decade cutting federal deficits $202 billion more than the House version passed in May.

No Senate Democrat supports the measure, though many have publicly acknowledged insurance under ObamaCare has become too expensive and offers Americans too few options.

Senate Minority Leader Chuck Schumer chided Senate Republicans after McConnell's announcement Tuesday but acknowledged they are determined to prevail.

"This Republican bill is rotten to the core. ... We know the fight is not over," said the New York Democrat, who also suggested McConnell will "cut back-room deals" and use a slushfund to "buy off" unsupportive GOP senators.

The CBO projected the House version would leave 23 million more Americans uninsured, which prompted President Trump to call the measure mean and prod the Senate to produce a package with more "heart."

Trump reportedly phoned some GOP senators before calling for the White House meeting, after largely steering clear of helping McConnell and his 12-member team write the bill behind closed doors.

McConnell said Tuesday that Trump has been "fully engaged" throughout the process and that his input has been "helpful."

Fox News' Chad Pergram and Joseph Weber and The Associated Press contributed to this report.