WASHINGTON — One key unsettled issue stalling progress on President Donald Trump’s big bill in Congress is particularly daunting: How to cut billions from health care without harming Americans or the hospitals and others who provide care?

Republicans are struggling to devise a solution to the health care problem their package has created. Already, estimates say 10.9 million more people would be without health coverage under the House-passed version of the bill. GOP senators have proposed steeper reductions, which some say go too far.

“The Senate cuts in Medicaid are far deeper than the House cuts, and I think that’s problematic,” said GOP Sen. Susan Collins of Maine.

Senators have been meeting behind closed doors and with Trump administration officials as they rush to finish up the big bill ahead of the president’s Fourth of July deadline. Much of the package, with its tax breaks and bolstered border security spending, is essentially drafted. But the size and scope of healthcare cuts are among the toughest remaining issues.

It’s reminiscent of the summer during Trump’s first term, in 2017, when Republicans struggled to keep their campaign promise to “repeal and replace” the Affordable Care Act, or Obamacare, only to see the GOP splinter over the prospect of Americans losing health coverage. That legislation collapsed when then-Sen. John McCain famously cast a thumbs-down vote.

Senate Majority Leader John Thune is determined to avoid that outcome, sticking to the schedule and pressing ahead with voting expected by the end of the week.

“This is a good bill and it’s going to be great for our country,” Thune said, championing its potential to unleash economic growth and put money in people’s pockets.

The changes to the federal health care programs, particularly Medicaid, were always expected to become a centerpiece of the GOP package, a way to offset the costs of providing tax breaks for millions of Americans. Without action from Congress, taxes would go up next year when current tax law expires.

The House-passed bill achieved some $1.5 trillion in savings overall, a large part of it coming from changes to health care. The Medicaid program has dramatically expanded in the 15 years since Obamacare became law and now serves some 80 million Americans. Republicans say that’s far too high, and they want to shrink the program back to a smaller size covering mainly poorer women and children.

House Democratic Leader Hakeem Jeffries said Republicans are “trying to take away healthcare from tens of millions of Americans.” Democrats are uniformly opposed to what they call the “big, ugly bill.”