President Joe Biden gave a stark warning to the nearly 1,000 federal employees and staff he appointed on his first day in office.
Be respectful to colleagues, he said, or you’re out.
"If you're ever working with me and I hear you treat another colleague with disrespect, talk down to someone, I promise you, I will fire you on the spot," Mr Biden said in a virtual ceremony in the State Dining Room of the White House. He spoke from behind a lectern, while the appointees appeared at the event via video streams set up on a series of television screens.
He reminded them that “we work for the people” and called on them to be “decent, honourable and smart”.
The message contrasted with the previous administration with a president accused by critics of misogyny, belittling opponents, disrespecting the public and his office. There were also reports from within the White House of commonplace bullying by senior officials – something denied by the administration.
The new president also told the group that “we have such an awful lot to do” and said that containing the pandemic and administering Covid-19 vaccines will be the “most consequential logistical thing that’s ever been done in the United States”.
He said he expected “to make mistakes” but promised during the swearing in that he will “acknowledge them” when he does.
Meanwhile, after arriving, Mr Biden said that Donald Trump had left him a "very generous letter" before leaving Washington before the inauguration on Wednesday.
"The president wrote a very generous letter. Because it was private, I will not talk about it until I talk to him," he said.
The remarks came after Mr Biden signed three executive actions, including a requirement to wear face masks on federal property and a measure that would re-enter the US into the Paris Agreement on climate change.
The signing was the first time since being sworn in that Mr Biden had been available to the press in the Oval Office, where some decor from the previous administration has been replaced.
He sat at the Resolute desk, the same desk Mr Trump, Barack Obama and several other presidents have used.
Busts of Martin Luther King Jr and Robert F Kennedy, whose careers inspired Mr Biden’s work in public service, flanked the room’s fireplace.
On a table behind the desk were pictures of Mr Biden’s family and a bust of the labour leader Cesar Chavez.
Mr Trump left Washington early on Wednesday and arrived at his Mar-a-Lago resort in Palm Beach, Florida, before Mr Biden was sworn in to replace him in the White House.
Meanwhile, the president’s press secretary, Jen Psaki, held her first news conference just seven hours after Mr Biden's inauguration, vowing to bring truth and transparency back to government.
While Mr Trump and his top aides had an often stormy relationship with what they called "the fake news media", Ms Psaki pledged a professional, civil exchange.
"There will be moments when we disagree, and there will certainly be days where we disagree for extensive parts of the briefing," she said. "But we have a common goal, which is sharing accurate information with the American people."
Mr Biden plans to "bring transparency and truth back to the government to share the truth, even when it's hard to hear", she said.
Ms Psaki said she expected to hold daily briefings at the White House on weekdays, and to make health officials available to explain efforts to get the Covid-19 pandemic under control.
Under Mr Trump, the White House banned news organisations it viewed as too critical from briefings and moved to off-camera gaggles instead of daily televised news briefings.