Donald Trump says millions will benefit from changes to health care law
President Donald Trump has predicted "millions and millions of people" will benefit from his action to unwind the health care law.
Mr Trump has signed an executive order to make lower-premium plans more widely available.
But the changes Mr Trump hopes to bring about could take months or even longer and the proposals may not be finalised in time to affect coverage for 2019, let alone next year.
White House domestic policy director Andrew Bremberg said Mr Trump still believes Congress needs to repeal and replace the Obama-era Affordable Care Act.
The White House described the order as first steps.
Mr Trump signed the order in the White House's Roosevelt Room surrounded by Vice President Mike Pence, members of his Cabinet and Congress.
The president says the order will provide what he calls "Obamacare relief" for millions.
Mr Trump is relying on the executive order because the Republican-controlled Congress has been unable to pass a plan to repeal and replace the Obama-era health care law.
Mr Trump says the health care system "will get better" with his action, and the action will cost the federal government nothing.
But he says his order will give people more competition, more choices and lower premiums.