Taylor Swift and Randy Newman perform special duet at Toy Story 5 premiere

Taylor Swift performed a duet with Randy Newman at the world premiere of Toy Story 5 in Los Angeles on Tuesday night.

Before a screening of the fifth instalment of Pixar's Toy Story film series, the music superstar took to the stage to sing I Knew It, I Knew You at a piano.

Taylor wrote and produced the single for the movie with her close collaborator Jack Antonoff, with the track inspired by the character of Jessie.

In addition, the Opalite hitmaker was joined by the franchise's long-running composer Randy for a rendition of his 1995 track, You've Got a Friend in Me.

The theme song has been incorporated into the soundtracks of all of the Toy Story films, starting with the 1995 original.

Addressing the audience, Taylor thanked all the artists and animators who worked so hard on creating the feature.

"It means the world to me to be a small part of the universe of these films," she smiled. "Toy Story 5 is my favourite of all the Toy Stories. I'm so lucky I get to be a part of this. I want to thank all the creators at Disney and Pixar for all the work they put into this film. It's insanely beautiful. It's a masterpiece. We're so lucky to get have this film out. I hope you are all so proud of yourselves."

Members of the Toy Story 5 voice cast, including Tom Hanks, Tim Allen, and Joan Cusack, also were in attendance.

Speaking to Variety, Tom revealed that he didn't know Taylor had recorded I Knew It, I Knew You before the soundtrack dropped.

"It was top secret. We did not know until, literally, when the moment came. They ushered us into a soundproof room and said, 'Tonight at 9 p.m., the true end titles song is going to drop, and it's by Taylor Swift.' And I was like, 'You guys kept this from us all?' And we saw the movie without (the song), we had some dummy thing in there."

Toy Story 5 opens in theatres on 19 June.