The White House released an executive order Monday afternoon intended to require insurance companies, doctors and hospitals to give patients more information about precisely what their care will cost before they get it.

President Trump announced the new policy at a signing event, flanked by doctors and patients who had been hit by unexpected medical bills. The event came a week after the official launch of his re-election campaign, and it allows the president to make a claim that he is pursuing a far-reaching health reform plan, his answer to voter concerns about the high costs of care.

“We’re taking power away from bureaucrats, we’re taking it away from insurance companies and away from special interests, we’re giving that power back to patients,” he said, adding that the proposal would bring health care costs “way, way down.”

“We’re taking one more giant step towards a heath care system that is really fantastic.”

Mr. Trump was elected on a promise to repeal the Affordable Care Act, and he has continued to suggest that a plan to repeal the 2010 health law is around the corner, even after Republicans failed to pass several replacement bills in 2017. His attorney general is arguing in court that the entire law should be invalidated. But at Monday’s event, he sounded a more conciliatory note and said he had instructed the Health and Human Services secretary, Alex M. Azar II, to do “a great job” administering the Affordable Care Act.