Democrats signaled that they will seek to secure payments owed to health insurers under the Affordable Care Act as part of pending negotiations over a government spending bill Thursday — a new wrinkle in sensitive talks that emerged a day after President Trump threatened to use the payments to force Democrats to negotiate a replacement for the ACA.

The “cost-sharing reduction” payments are meant to subsidize out-of-pocket expenses for low-income Americans who receive insurance through ACA marketplaces, and the payments are seen as a key factor in maintaining the stability of the market for individual insurance in many states.

House Republicans sued the administration of President Barack Obama over the payments, and they have been tied up in litigation for months as insurers have warned that the impasse could threaten coverage for many Americans.

Trump told the Wall Street Journal on Wednesday that he might hold back the payments to force Democrats to negotiate over replacing the Affordable Care Act. “I don’t want people to get hurt,” he told the paper. “What I think should happen — and will happen — is the Democrats will start calling me and negotiating.”

Two Democratic aides familiar with the negotiations but not authorized to comment publicly on them said Trump’s remarks have now put the issue among the party’s top priorities as they negotiate a spending bill. Current federal appropriations expire April 28, and a partial government shutdown would follow if Republicans and Democrats cannot agree on how to extend funding.

Both Senate Minority Leader Charles E. Schumer (D-N.Y.) and House Minority Leader Nancy Pelosi (D-Calif.) are determined to use Democrats’ leverage in the spending fight to force the Trump administration to make the insurance payments, the aides said.

Republicans have their own demands — including funding for the southern border wall supported by Trump and also a provision that could block federal funding for “sanctuary cities” that do not cooperate with federal immigration authorities. But any spending bill will have to win some Democratic support to reach a 60-vote threshold in a chamber where Republicans have a 52-vote majority.

Trump maintained Wednesday that he, not Democrats, hold the leverage: “Schumer should be calling me up and begging me to help him save Obamacare,” he told the Journal. “He should be calling me and begging me to help him save Obamacare, along with Nancy Pelosi.”

A Pelosi aide said Trump’s stance on withholding the payments “will increase costs, is a threat to the good health of the American people and a threat to keeping government open.”

Stephen Worley, a spokesman for Senate Appropriations Committee Chairman Thad Cochran (R-Miss.), declined to comment.

House Speaker Paul D. Ryan (R-Wis.) indicated last month that House Republicans had no plans to drop their lawsuit, which challenged the authority of the executive branch to make the payments absent a congressional appropriation but he did acknowledge the Trump administration had the authority to continue the payments while the lawsuit is resolved. “We continue to work with the Trump administration to evaluate the options in front of us,” Ryan spokeswoman AshLee Strong said Thursday.

Sen. Ron Wyden (D-Ore.), the top Democrat on the Senate Finance Committee, said Thursday that Democrats “will not negotiate with hostage takers.”

“There is no outcome in which the administration sabotaging insurance markets persuades Democrats to pass Trumpcare, a disastrous proposal which would only make our health care system worse,” Wyden said in a statement responding to Trump’s remarks. “When the president drops his threats on Americans’ health care — including the latest threat to withhold insurance payments, which he clearly understands puts people’s care in danger — Democrats will be prepared to work on bipartisan improvements to the Affordable Care Act.”