President Donald Trump has quickly assumed the mantle of the White House, making his first executive order one aiming to axe his predecessor's signature healthcare law.
Hours after delivering a stinging rebuke of the political status quo in his inaugural address, Mr Trump sat at the president's formal desk in the Oval Office as he signed the order.
White House chief of staff Reince Priebus said it was aimed at "minimising the economic burden" of the "Obamacare" law.
The order notes that Mr Trump intends to seek the "prompt repeal" of the law.
But in the meantime, it allows the Health and Human Services Department and other federal agencies to delay implementing any piece of the law that might impose a "fiscal burden" on states, health care providers, families or individuals.
Moments later, Vice President Mike Pence administered the oath of office to Defence Secretary James Mattis and Homeland Security Secretary John Kelly, the first members of Mr Trump's Cabinet to clear Senate confirmation.
The swearing-in ceremonies came amid a hectic set of activity late on Friday, before Mr Trump was to attend three inaugural balls.
As Mr Trump signed the paperwork, the White House announced Mr Priebus had sent a memorandum to agencies and departments outlining guidelines for slowing regulations.
Asked about his first day as president, Mr Trump said: "It was busy but good - a beautiful day."