Vice President Joe BidenJoe BidenBiden: Predicting Trump foreign policy 'like a Rubik's cube' Poll: Obama leaves office with 58 percent favorability Biden prays Trump will continue cancer moonshot MORE was sworn in for his second term on Sunday.
Supreme Court Justice Sonia Sotomayor administered the oath of office to Biden in the Naval Observatory, the vice president’s official residence.
The ceremony, which was attended by 120 guests, began with Rev. Kevin O’Brien, S. J., vice president for mission and ministry at Georgetown University, delivering a blessing.
"Amid all the complexities of our world, a world so beautiful but also broken, give him a share of your wisdom so that he can know what is good and give him the courage to always do what is right,” said O’Brien, offering a prayer for the vice president.
“Empower him to be a voice for those without a voice, and to labor tirelessly for a more just and gentle world. Empower him to be a voice for those without a voice, for those on the margins, those so easily overlooked, for you will judge us all by how we care for the least among us,” he added.
After Sotomayor administered the oath, Biden kissed the justice and thanked her.
He told guests that Sotomayor was due in New York City.
"I want to explain to you what a wonderful honor it was, and how much out of her way the Justice had to go. She is due in New York. She has to leave right now. So I apologize. We're gonna walk out," said Biden. "Her car's waiting so she can catch a train -- I hope I haven't caused her to miss.
Biden too had to leave to lay the ceremonial wreath at Arlington National Cemetery with President Obama.
“I will be back, they tell me, in 40 minutes. I hope some of you will still be here,” Biden said. “But I thank you very, very, very much for sharing this morning with Jill and me. And Madam Justice, it has been an honor. A great honor. Thank you.”
Before departing for Arlington, Biden asked his guests to “enjoy breakfast.”
At Arlington National Cemetery, Biden and Obama laid a wreath at the Tomb of the Unknowns. They were accompanied by Major General Linnington, according to a White House pool report.
As required by the Constitution, the president and vice president have to be sworn in on January 20. Because that date falls on a Sunday, Biden and President Obama are holding their official swearing-in ceremonies today.
Obama’s swearing in will be held at noon Sunday in the White House, where he will be joined by his family and Chief Justice John Roberts, who will administer the oath of office.
Organizers will hold a public swearing in during the ceremonies on Monday, where Sotomayor will again administer the oath of office to Biden and Roberts for Obama.
On Sunday evening, Biden and Obama will also deliver remarks at an inaugural reception to be held at the National Building Museum.
Before his swearing in, Biden celebrated mass at his residence accompanied by family members and guests.
Biden was sworn in using his family bible, according to The White House. The bible has been in the family since 1893 and Biden has used it every time he has been sworn in as a senator and when he took the oath of office as vice president in 2009.
Biden’s son, Beau Biden, also used the bible when he was sworn in as Delaware’s attorney general.
Among the guests at the swearing in were several lawmakers and senior aides.
Reps. Jim Clyburn (D-S.C.) and Debbie Wasserman Schultz (D-Fla.) were there, along with Sen. Bob CaseyBob CaseySenate Democrats brace for Trump era Senators introduce dueling miners bills Sanders to roll out bill letting Medicare negotiate drug prices MORE (D-Pa.) and New Hampshire Gov. Maggie Hassan (D).
Ex-White House Chief of Staff Bill Daley, senior Obama adviser David Axelrod, National Security Adviser Tom Donilon as well as AFL-CIO President Richard Trumka were also in attendance, according to a White House pool report.
A seat at the ceremony was reserved for former Sen. Chuck HagelChuck HagelWho will temper Trump after he takes office? Hagel: I’m ‘encouraged’ by Trump’s Russia outreach Want to 'drain the swamp'? Implement regular order MORE (R-Neb.), the president’s nominee to be the next Defense Secretary, but pool reporters did not see him at the event.
Democratic strategist Donna Brazile, who attended, praised the event "a special occasion" in remarks to a reporter, according to the pool report.
"I've known Joe Biden for over 25 years and to witness his private swearing in with his friends, close friends and family, with Justice Sonia Sotomayor, I don't think it gets any better," said Brazile.
She also joked about Biden's future political aspirations.
"Let's just say I see a number of superdelegates here as well," she added.
Biden has hinted that he is considering a run for the Democratic nomination in 2016.
At an inauguration ball hosted by the Iowa State Society on Saturday, Biden misspoke, telling supporters he was "proud to be president," and fueling further speculation about his future.
Meghashyam Mali contributed
This story was last updated at 9:54 a.m.