WASHINGTON — Top Senate Democrats rejected White House demands Friday to add provisions weakening the Obama health care law to a bipartisan deal on steadying unsettled insurance markets. The compromise already faced an uphill path and this was the latest blow.

Senate Minority Leader Chuck Schumer, D-N.Y., said the Trump administration was involved in the negotiations that produced the accord and “should support it instead of floating other ideas that would further the sabotage both parties are trying to reverse.”

Sen. Patty Murray of Washington, lead Democratic author of the agreement, said, “I’m certainly not interested in changing our bipartisan agreement to move health care in the wrong direction.”

The two Democrats were reacting to a White House official who said the measure must provide language lifting the tax penalties President Barack Obama’s Affordable Care Act imposes on people who don’t buy coverage and employers who don’t offer plans to employees. The White House also wants provisions making it easier for people to buy low-premium policies with less coverage, said the official, who was not authorized to describe the demands on the record.

Such language would be a clear deal-breaker for Democrats, who have helped defeat repeated Republican efforts this year to scuttle Obama’s 2010 statute, one of his crowning achievements.

Murray reached agreement last week with Sen. Lamar Alexander, R-Tenn., for a two-year extension of federal payments to insurers that President Trump has blocked. The measure would also give states modest new flexibility to let insurers sidestep some coverage requirements under Obama’s law.

Failure to restore the money is already leading many insurers to boost premiums and is threatening to chase others out of unprofitable markets around the country.

Obama’s statute requires carriers to lower out-of-pocket costs for poorer customers and the government to reimburse them. A federal judge has found the payments weren’t properly approved by Congress, but Obama and Trump continued them until Trump halted them last week.

Trump’s position on the bipartisan deal has confounded Democrats and Republicans alike. He’s alternately praised and condemned the effort.