In an interview in the Oval Office, Mr. Trump said the White House may lack authority to make the payments established under his predecessor to reduce copayments and deductibles for some of the poorest customers who buy insurance under the 2010 Affordable Care Act. Cutting off the payments could trigger turmoil in insurance markets.

“I don’t want people to get hurt,” Mr. Trump said. “What I think should happen—and will happen—is the Democrats will start calling me and negotiating.”…

Mr. Trump said recent reports of infighting among his senior staff—particularly chief strategist Steve Bannon and son-in-law and senior adviser Jared Kushner—were “overblown.” But he referred to Mr. Bannon as “a guy who works for me” and noted that he, Mr. Trump, was his own “strategist.”

He also said Sean Spicer, his press secretary, “made a mistake” in saying Syrian President Bashar al-Assad committed atrocities worse than Nazi leader Adolf Hitler. Mr. Spicer has issued several apologies since.