WASHINGTON (AP) — In a gamble with monumental political stakes, Republicans set course for a climactic House vote on their health care overhaul after President Donald Trump claimed he was finished negotiating with GOP holdouts and determined to pursue the rest of his agenda, win or lose.

House Speaker Paul Ryan set the showdown for Friday, following a nighttime Capitol meeting at which top White House officials told GOP lawmakers that Trump had decided the time for talk was over.

"We have been promising the American people that we will repeal and replace this broken law because it's collapsing and it's failing families. And tomorrow we're proceeding," Ryan tersely told reporters after scheduling what loomed as the most momentous vote to date for Trump and for the Wisconsin Republican's own speakership.

In an embarrassing and stinging setback hours earlier, leaders abruptly postponed the vote because a rebellion by conservatives and moderates would have doomed the measure. They'd hoped for a roll call Thursday, which marked the seventh anniversary of President Barack Obama's enactment of his landmark health care statute that Republicans have vowed ever since to annul.

There was no evidence that leaders had nailed down sufficient support to prevail, nor that their decision to charge ahead was a feint and that they'd delay again if necessary. But they seemed to be calculating that at crunch time, enough dissidents would decide against sabotaging the bill, Trump's young presidency and the House GOP leadership's ability to set the agenda, with a single, crushing defeat.

"The president has said he wants the vote tomorrow," White House budget chief Mick Mulvaney told the lawmakers, according to Rep. Chris Collins, R-N.Y., a Trump ally. "If for any reason it goes down, we're just going to move forward with additional parts of his agenda. This is our moment in time."

Even if they prevail, Republicans face an uphill climb in the Senate, where conservatives and moderates are also threatening to sink it.

The GOP bill eliminates the Obama statute's unpopular fines on those who do not obtain coverage and the often generous subsidies for those who purchase insurance.

Instead, consumers would face a 30 percent premium penalty if they let coverage lapse. Republican tax credits would be based on age, not income. The bill would also end Obama's Medicaid expansion and trim future federal financing for the federal-state program and let states impose work requirements on some of its 70 million beneficiaries.

In a bid to coax support from conservatives, House leaders proposed a fresh amendment — to be voted on Friday — repealing Obama's requirement that insurers cover 10 specified services like maternity and mental health care. Conservatives have demanded the removal of those and other conditions the law imposes on insurers, arguing they drive premiums skyward.