US President Barack Obama Sunday began his second term in office, laying his hand on wife Michelle's family Bible to take the oath at a private ceremony at the White House, dpa reported.
Obama, 51, the nation's 44th president and only the 17th to be elected to a full second term, was sworn in by Supreme Court chief justice John Roberts at an intimate gathering before a few reporters and family members, including wife Michelle and daughters Malia, 14, and Sasha, 11.
"I did it," Obama commented, before leaving the room with his wife and daughters.
The big hoopla is reserved for Monday's public inauguration on the steps of the Capitol, before 250,000 ticketed onlookers near the podium where Obama will stand, in addition to 800,000 expected to jam the mall.
Sunday's private oath was necessary to fulfill the constitutional mandate that every presidential term begin at noon on January 20. By tradition dating back to 1821, when January 20 falls on a Sunday, the public celebrations are postponed to another day.
Earlier Sunday, Vice President Joe Biden was sworn in for his second term at his official residence at the Naval Observatory in north-west Washington. Justice Sonia Sotomayor, whom Obama appointed as the first Hispanic on the Supreme Court, administered the oath.
Before Obama's swearing-in on the sparkling, sunny day, Biden and Obama laid a wreath at the Tomb of the Unknowns at Arlington National Cemetery, burial place of the nation's military heroes and veterans.
In 2009, at Obama's first inauguration, both Roberts and Obama made some mistakes and the oath had to be repeated the next day at the White House.
On Sunday, Roberts read the oath from a prepared text.