President Donald Trump quickly assumed the mantle of the White House on Friday, making his first executive order one aimed at his predecessor's signature health care law and swearing-in members of his national security team to his Cabinet.
Hours after delivering a stinging rebuke of the political status quo in his inaugural address, Trump sat at the president's formal desk in the Oval Office as he signed the order that White House chief of staff Reince Priebus said was aimed at "minimizing the economic burden" of the "Obamacare" law.
The order notes that 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.
The swearing-in ceremonies came amid a hectic set of activity late Friday, before Trump was to attend three inaugural balls. As Trump signed the paperwork, the White House announced Priebus had sent a memorandum to agencies and departments outlining guidelines for slowing regulations.
Asked about his first day as president, Trump said, "It was busy but good — a beautiful day."
Although Trump campaigned on a detailed 18-point plan of things to do on Day One, he has since backed off some of his promised speed, downplaying the importance of a rapid-fire approach to complex issues that may involve negotiations with Congress or foreign leaders. Trump has said that he expects Monday to be the first big workday, his effective Day One.
On Friday, he switched between the official business of governing and the pageantry of his inauguration, making his first official moves as president in an ornate room steps from the Senate floor. Flanked by Pence and congressional leaders before his congressional luncheon, Trump praised each of his Cabinet nominees as he signed the papers formalizing their nominations. He also engaged in banter with his new congressional rivals, including Senate Democratic leader Chuck Schumer of New York and House Democratic leader Nancy Pelosi of California.
Trump also signed a proclamation declaring a national day of patriotism, according to a tweet from White House spokesman Sean Spicer.
Priebus' memo says that agencies shouldn't submit any regulations to be published in the Federal Register unless a Trump-selected agency head approves it. That appears to mean that some regulations that had been approved by President Barack Obama's administration would be halted. It also freezes any regulations that are already in the pipeline to be published and allows time for other pending regulations to be reviewed by Trump's administration.
The memo is similar to one that Obama's chief of staff issued the day Obama was inaugurated in 2009.
Before Mattis could be nominated, Trump had to sign a bill passed by Congress last week granting a one-time exception from federal law barring former U.S. service members who have been out of uniform for less than seven years from holding the top Pentagon job. The restriction is meant to preserve civilian control of the military.
Mattis, 66, retired from the Marine Corps in 2013. Hours later, he was confirmed by the Senate as Trump watched his inaugural parade from a stand outside the White House. The Senate later confirmed retired Gen. John Kelly to lead the Homeland Security Department.
There were others signs his new government was up and running. Federal websites and agencies immediately began reflecting the transfer of power, and WhiteHouse.gov was revamped for Trump's policy priorities as pages about LGBT rights and the Obama administration's climate change plan were eliminated.
Shortly after Trump became president, the Department of Housing and Urban Development suspended the Obama administration's planned reduction of mortgage insurance premium rates, a move that had been intended to make buying a home more affordable.
More significant policy announcements are expected in the early days of the Trump administration.
Trump's spokesman has said the president intends to withdraw from the 12-nation Trans-Pacific Partnership deal, which he views as detrimental to U.S. businesses and workers. He has also promised to renegotiate the two-decades-old Clinton era North American Free Trade Agreement or withdraw from it.
Given Trump's opposition to Obama's immigration actions, he could also cancel the Deferred Action for Childhood Arrivals program, or DACA, which has protected about 750,000 young immigrants from deportation. The program also offered those immigrants work permits.
Trump also faces an early choice of naming a Supreme Court justice to fill the vacancy left by the late Justice Antonin Scalia. Trump has said he will announce a nominee in about two weeks.
Other issues poised to receive early action include energy, where Trump is likely to undo regulations on oil drilling and coal, and cybersecurity, where he has already said he will ask for a report on the strength of the nation's cyber defenses within 90 days of taking office.
Associated Press writer Alicia A. Caldwell contributed to this report.