WASHINGTON — President Trump’s decision to cut off critical payments to health insurance companies ratcheted up the pressure on Congress on Friday to take action to protect consumers from soaring premiums, while also adding a combustible new issue to negotiations to avert a government shutdown this year.

Mr. Trump’s move, announced Thursday night, could cause chaos in insurance markets, sending insurers fleeing from the Affordable Care Act’s marketplaces, raising the federal government’s costs and pricing out some consumers. It came just hours after he signed an executive order that also undermined the health law by encouraging the development of lower-cost insurance policies not subject to the Affordable Care Act’s rigorous coverage standards.

But the president suggested on Friday that he was trying to get Democrats to the negotiating table.

“If the Democrats were smart, what they’d do is come and negotiate something where people could really get the kind of health care that they deserve,” Mr. Trump told reporters, insisting that the subsidies were “making insurance companies rich.”