(CNN) Republican congressional leaders rejected Friday any hint from the White House that they should disrupt their carefully crafted bill to repeal and replace Obamacare.

After CNN reported Thursday night that President Donald Trump was open to moving up the sunset of the Medicaid expansion up from 2020 to the end of this year, GOP leaders supporting the bill are still committed to their original plan.

"I think right now that would be very difficult to do," Majority Leader Kevin McCarthy told reporters in a news conference Friday morning on Capitol Hill.

Republican leaders in Congress warn that making changes to the Medicaid provision could seriously imperil the legislation among more moderate members and perhaps still not be enough to assuage the most stringent conservatives.

Reforming the Medicaid expansion allowed under the Affordable Care Act has becomes one of the most contentious hurdles for lawmakers repealing the Affordable Care Act. Not only are there conservative and moderate Republican interests at odds, but the wishes of non-expansion state and expansion-state lawmakers are in direct conflict. The Kaiser Family Foundation estimates that nearly 11 million people have become insured because of the expansion, people who moderates and expansion states lawmakers have argued cannot be left out in the cold as a consequence of the GOP bill.

Rep. Tom MacArthur, a Republican from New Jersey and co-chair of the moderate Tuesday Group, said that moving up the Medicaid expansion sunset could cost votes.

"We are giving states more time and people, more importantly, more time to move into the Medicaid expansion opportunity. I think the current date is better and I don't like the idea of making it shorter," MacArthur said. "I think the needle leadership is trying to thread right now is exactly that between people who want to take things out of the bill and make it less than it is and those of us who are already struggling with the effectiveness on the most vulnerable. "

While Trump has hinted he's open to changing the Medicaid provision, Republican leadership has kept tight control of this process. This week, both the House's Ways and Means and the Energy and Commerce's Committees voted along party lines to advance the substance of the legislation as it was originally written. Rep. Joe Barton, a Republican from Texas, had threatened to introduce an amendment rolling back Medicaid expansion to the end of this year, but even he ended up pulling it. And as a senior Republican aide pointed out, three freedom caucus members who serve on the committees voted for the bill without changes.

Friday morning there was some agitation that Trump was adding a bit of unpredictability to a process House leaders had managed effectively up till this point.

The insinuation Friday morning from members was that the White House had worked hand-and-hand with Hill leaders to negotiate this package even though some conservatives in the House -- as well as several senators -- have publicly criticized the bill since it was introduced Monday.

When asked Friday if Trump's comments had changed the dynamics on Medicaid, Rep. John Shimkus, a Republican from Illinois on Energy and Commerce said that just because Trump was open to it, didn't mean other members would be.

"Maybe he is. I'm not sure all the members are," Shimkus said.

Energy and Commerce Committee Chairman Greg Walden vehemently defended the Medicaid portion of the bill as it is written now saying that it came after consultation with governors, insurance commissioners and the White House.

"What we want to make sure is we don't create any gaps here," Walden said. "Our best effort is what you see before us."

McCarthy reiterated that Trump supported the bill and wanted the bill to pass.

"Why shouldn't the President communicate and listen to members?" McCarthy asked. "If we're going through three different phases why wouldn't we continue to listen to them? Why wouldn't we continue to work together?"

Republican leaders have said at every turn that the House bill to repeal Obamacare is just the first step in their plans to reform health care. They also plan to have Health and Human Services Secretary Tom Price use his authority at the agency to make changes at the administrative level. Then, members will be able to move additional legislation on the floor through regular order. The obstacle on that, however, is that those pieces of legislation will require 60 votes in the Senate, not the 51 required through the process of reconciliation. Getting Democrats on board with Republican health care bills will be a major and perhaps, impossible lift

GOP leaders are aiming to finish the legislative process with the proposal by the mid-April Easter recess.