Joe Biden is preparing to be sworn in as the 46th US president, ending one of the most dramatic political transitions in American history. He is due to take the oath of office at about 12:00 local time (17:00 GMT). Outgoing President Donald Trump, who has not formally conceded to Mr Biden, is snubbing the ceremony. The new president has announced a raft of executive orders aimed at dealing with the coronavirus crisis and reversing Mr Trump's key policies. Mr Trump left the White House for the last time as president shortly after 08:00 (13:00 GMT). He boarded a helicopter, flew to the nearby Andrews base, and is now flying to Florida. He is the first president not to attend his successor's inauguration since 1869. Mr Biden, a Democrat, will take the oath of office outside the US Capitol. There is extra-tight security after the building was stormed by violent pro-Trump protesters in a deadly riot on 6 January. Some 25,000 troops are guarding the inauguration ceremony, which will be missing the traditional hundreds of thousands of spectators because of the coronavirus pandemic. Alongside Mr Biden, Kamala Harris will make history when she is sworn in as the nation's first female vice-president.