Vice President Joe Biden made a special appearance at the Oscars ceremony on Sunday to advocate for victims of sexual assault and introduced a powerful performance by Lady Gaga that featured survivors of sexual abuse.

Biden came on stage to rousing applause, quipping "I'm the least qualified man here tonight" before he addressed the issue of sexual assault.

"Despite significant progress over the last few years, too many women and men on and off college campuses are victims of sexual abuse," Biden said.

He then asked the audience to join him, President Barack Obama and survivors of abuse in taking the pledge to "intervene in situations when consent has not or cannot be given."

"We must and we can change the culture so that no abused woman or man - like the survivors you see here tonight - ever feel like they have to ask themselves, 'What did I do?' They did not do anything wrong."

Biden then introduced Lady Gaga as "my friend and a courageous lady herself."

Gaga, dressed in white and playing a white grand piano, performed her Oscar-nominated song "Til It Happens to You," from the documentary "The Hunting Ground," which investigated widespread sexual assault on American college campuses.

In a red carpet interview televised on ABC prior to the show, Gaga identified herself as "a survivor" and expressed her appreciation for the opportunity to perform the song and spread awareness. "I'm very grateful to the Academy for giving us this world stage to reward survivors for being brave and coming forward," she said.

Dozens of victims of sexual abuse appeared on stage holding hands behind Gaga and received a standing ovation.

"Til It Happens to You" lost out to the latest James Bond theme song "Writing's On The Wall" performed by Britain's Sam Smith, who acknowledged Gaga in his acceptance speech, calling her "incredible."

Gaga returned to the Oscars stage a year after she led the Academy's tribute to the "Sound of Music," singing a medley of classic songs from the musical film.

Gaga's Oscar performance comes on the heels of a busy month for the singer, who earned praise for her rendition of the national anthem at the Super Bowl.

The six-time Grammy winner, known for pop songs such as "Bad Romance" and "Born This Way," also performed a psychedelic tribute to the late singer David Bowie at the Grammy Awards, channeling his signature androgynous look.