Republicans' new push to repeal Obamacare without implementing an immediate replacement has already appeared to stall as three GOP senators said they would not vote for it to move forward, for now.

After the collapse Monday night of the latest GOP plan to replace Obamacare, Senate Majority Leader Mitch McConnell said he aimed to pass a bill to repeal the law and then pass a replacement during a "stable two-year transition period." The GOP-controlled Congress voted to do so in 2015 knowing that then-President Barack Obama would veto the bill.

Within hours of when he started that push, members of his caucus said they could not back the repeal-first goal. Sens. Susan Collins, R-Maine, Shelley Moore Capito, R-W.V., and Lisa Murkowski, R-Alaska, said they would not support a repeal bill without a replacement.

Republicans hold 52 seats in the Senate, and passing a plan under budget reconciliation rules requires 50 votes, with Vice President Mike Pence breaking a tie. Sen. John McCain, R-Ariz., is away from the Senate recovering from surgery, so losing two votes or more will stall a Republican plan, for now.

Still, McConnell insisted Tuesday that he wants to vote on a repeal-only bill in the "near future" amid what he described as a "very challenging experience."

"As of today we just simply do not have 50 senators who can agree on what ought to replace the existing law," McConnell told reporters after a Senate GOP lunch. "What we do have is a vote that many of us made two years ago at a time when the president of the United States would not sign the legislation that would repeal Obamacare and with a two-year delay give us an opportunity to build something better on a bipartisan basis. That's what I sense most of our members would like to vote on now and we'll be doing that in the near future."

The GOP's effort to repeal and replace Obamacare, a Republican campaign promise for most of the last decade, has stalled multiple times this year amid party divisions. The GOP chose to address the health-care overhaul before it took on tax reform, another key campaign plank, and every setback is seen as delaying the party's broader agenda.

President Donald Trump initially urged lawmakers to pass a repeal plan and then figure out a replacement later. After the plan stalled Tuesday, he told reporters that "we'll just let Obamacare fail."

"We're not going to own it. I'm not going to own it," Trump said, deflecting blame to Democrats despite Republicans' failure to reach a consensus within the party.

Collins said Tuesday that she would oppose even a procedural motion to start debate on the proposal. Capito added that she would only support the motion to proceed if she is "confident there is a replacement plan that addresses [her] concerns."

Capito: MORE: I will only vote to proceed to repeal legislation if I am confident there is a replacement plan that addresses my concerns.

Collins told reporters Tuesday that she fears the effects of repealing Obamacare without a replacement.

"I voted against this approach in 2015, and I do not think that it is going to be constructive to repeal a law that at this point that is so interwoven within our health-care system and then hope that over the next two years we will come up with some kind of replacement."

Murkowski told NBC News that she is "not there" on a motion to proceed.

"I said in January that we should not repeal without a replacement and just an indefinite hold on this just creates more chaos and confusion," she told NBC.

Sen. Lamar Alexander, R-Tenn., chairman of the Senate committee that oversees health care issues, said Tuesday that he will push to hold hearings on the best ways to stabilize the individual insurance market "however the vote comes out" on the health-care bill.

The Senate's Obamacare replacement plan that collapsed Monday night faced skepticism from both GOP conservatives who wanted a full repeal and moderates who largely feared its potential effects on coverage and costs. Four Republicans — Collins, Rand Paul of Kentucky, Mike Lee of Utah and Jerry Moran of Kansas — opposed the motion to proceed on that plan before McConnell shifted to pushing repeal without an immediate replacement.

While repeal-first appealed more to GOP conservatives such as Lee, moderates such as Collins, Capito and Murkowski have expressed concerns about it.

Sen. Rob Portman, R-Ohio, also expressed doubts Tuesday about a repeal without a replacement but did not say whether he would support the bill.

"If it is a bill that simply repeals, I believe it will add to more uncertainty," he told reporters.

On Tuesday, Senate Minority Leader Chuck Schumer again urged Republicans to work with Democrats on passing a plan to stabilize insurance markets and lower costs. He contended that passing a repeal without a replacement "would be a disaster" and cause the health-care system to "implode."