Former President Bill Clinton and Hillary Clinton, who lost to Trump in November's presidential election, have arrived for the inauguration.
The Obamas and Trumps are said to be preparing to leave the White House. They will travel by motorcade to the U.S. Capitol, the seat of both houses of Congress and the site of the inauguration ceremony, which scheduled to begin in about an hour.
At 70 years old on Inauguration Say, Donald J. Trump will become the oldest person in U.S. history to be sworn in as president. Here is a comparison with past U.S. presidents. (Click to see full infographic)
Trump supporters in Washington for the inauguration festivities.
A Trump supporter talks to our correspondent Mike Eckel.
BBC's Steve Rosenberg on comments made by Russia's flamboyant ultranationalist lawmaker Vladimir Zhirinovsky:
Several polls in the days ahead of the inauguration suggested Donald Trump will be the least popular newly minted president in history, with an approval rate of around 40-44 percent.
Trump has dismissed the polls, reminding the public that few people predicted his election victory in November.
MSNBC's Christopher Hayes comments on the low turnout prior to Trump's inauguration.