WASHINGTON (REUTERS) - United States Vice-President Joe Biden took the oath of office for his second term at a small ceremony at his official residence, using a bible with a Celtic cross on the cover that had been in his family since 1893.
Mr Biden chose Supreme Court Justice Sonia Sotomayor to swear him in, making her the first Hispanic judge to ever administer an oath of office for one of the nation's two highest offices.
Mr Biden's family, about 120 guests and a few reporters witnessed the private ceremony.
The US Constitution requires the President and Vice-President to be sworn in on Jan 20.
Mr Obama and Mr Biden will repeat their oaths on Monday during a public ceremony at the US Capitol. The ceremony will be followed by Mr Obama's inaugural address and the inaugural parade down Pennsylvania Avenue, from the Capitol to the White House.