President Donald Trump reacts as he sits on a truck while he welcomes truckers and CEOs to attend a meeting regarding healthcare at the White House in Washington, D.C., March 23, 2017. Reuters

President Donald Trump told four of his close associates that he regrets his campaign pledge to prioritize repealing and replacing the Affordable Care Act, or Obamacare, sources close to the Trump administration told the New York Times Thursday. Instead, Trump reportedly complained that he should have first focused on implementing legislation that would provide tax cuts to the middle class—something his Republican base could have rallied behind.

The news came as the Obamacare replacement plan faced an uphill battle in its House vote, with several Republican members of Congress publicly denouncing the potential bill for not covering enough people. Congressional Republicans postponed a vote on the replacement bill scheduled to take place Thursday despite House Speaker Paul Ryan’s attempts to garner support among conservative members.

Read: Is Obamacare Working? Obama Defends Affordable Care Act As Republicans Scramble To Replace It

That reportedly infuriated Trump, who warned if the House didn’t vote on the legislation Friday, he would see to that President Barack Obama’s signature healthcare law remained intact. Trump’s closest advisor, chief strategist Steve Bannon and National Economic Council director Gary Cohn, both stood behind the president’s ultimatum, the New York Daily News reported Friday.

Republican lawmakers introduced a replacement bill earlier this month that would strip the mandate requiring all Americans to have health insurance, as well as cut the federal-state Medicaid program for low earners, CNN reported Thursday. The new bill would offer refundable tax credits so that citizens can buy their own insurance plan instead of implementing a fine on Americans for not being covered.

The bill needed 218 Republican votes to pass the House if they fail to get any Democrats to join. Many Congressional Republicans were fearing the political ramifications of the replacement plan stripping healthcare from voters in their home states, with 24 GOP members publicly saying they would vote against it as of Friday morning.

More than 20 million Americans have gotten health insurance since the Affordable Care Act became law in 2010, Obama touted in a statement Thursday. And more than 90 percent of Americans were covered as of 2015, according to data from the U.S. Census Bureau from September 2016.

If Trump were to completely repeal the Affordable Care Act, 19.7 million Americans would lose their insurance by 2018, according to a Commonwealth study. If legislation passed to allow people with pre-existing conditions to be dropped, roughly 54 million citizens under 65 would lose healthcare, a Kaiser Family Foundation study released in December found.

Democratic House Minority Leader Nancy Pelosi, who was instrumental in getting the Affordable Care Act passed in the House in 2010, told the New York Times that Trump's threats to get Congressional Republicans to vote for the replacement plan was a "rookie" mistake.

"He seems to think that a charm offensive or a threat will work," Pelosi said. "That's not the way it works. You have to build real consensus, and you have to gain a real knowledge of the policy — and the President hasn't done either of those things."