US Senate Majority Leader Mitch McConnell speaks to the media about plans to repeal and replace Obamacare on Capitol Hill in Washington, DC, US on June 27, 2017. [Photo/Agencies]

WASHINGTON - Three Republican senators said Tuesday they would oppose moving ahead on a new GOP plan only aiming to repeal Obamacare, leaving Republicans once again short of votes needed to carry on with their seven-year-old drive.

Lisa Murkowski, Shelley Moore Capito and Susan Collins indicated Tuesday that they would not vote to move forward a GOP repeal of the Affordable Care Act, known as the Obamacare, to the Senate floor without implementing an immediate replacement.

Their opposition came after Senate Majority Leader Mitch McConnell conceded failure in efforts to repeal and immediately replace the Obamacare late Monday night as more Republican senators defected against the revised Better Care Reconciliation Act (BCRA), a GOP bill designed to overhaul the Obamacare.

But McConnell said the Senate will vote to take up the House-passed bill in coming days while calling for a repeal vote on Obamacare with a two-year delay for substitute.

"I regret that the effort to repeal and immediately replace the failures of Obamacare will not be successful," McConnell said on the Senate floor Tuesday. "That doesn't mean we should give up."

However, members of McConnell's caucus said a repeal-only bill would not have their support, shortly after he made those remarks.

"My position on this issue is driven by its impact on West Virginians," Senator Capito said in a statement.

"With that in mind, I cannot vote to repeal Obamacare without a replacement plan that addresses my concerns and the needs of West Virginians," Capito said.

"To repeal there has to be a replacement," Senator Murkowski of Alaska told reporters. "There's enough chaos already, and this would just contribute to it."

Separately, Senator Collins of Maine said she was opposing the repeal and delay proposal as it is not constructive to repeal a law closely associated with the health care system but only plan to come up with a replacement over the next two years.

Republicans control a 52-48 majority in the 100-seat Senate. Under budget reconciliation rules, at least 50 votes are required to pass a plan, with Vice President Mike Pence to break a tie.

With Senator John McCain of Arizona recovering at home from surgery, two or more defections would stall any Republican proposal, were there a unanimous opposition from Democrats and independents.

The Senate's Obamacare replacement plan, the BCRA, collapsed Monday night when Collins and Senator Rand Paul of Kentucky were joined by Senator Mike Lee of Utah and Jerry Moran of Kansas in opposing the motion before McConnell shifted to advancing a repeal-only plan, stalled almost immediately the next day.

US President Donald Trump said Tuesday he was "very disappointed" with the defeat in advancing the Republican health care plan, one of his major campaign promises during the 2016 presidential elelction.

"Let Obamacare fail," he said. "We're not going to own it. I'm not going to own it. I can tell you the Republicans are not going to own it."

The GOP effort to repeal and replace the Obamacare has stalled mutiple times in past weeks.

Republicans are divided amid unsolved concerns of rising costs and fewer insurers once the BCRA was enacted, while Democrats argue the GOP bill would cost tens of millions of people's coverage.