Katy Perry duets with Elmo on Sesame Street

Katy Perry is to appear on a forthcoming episode of children's television show Sesame Street.

The singer duets with popular character Elmo on a reworked version of her hit single Hot N Cold.

Dressed in a green princess costume, Perry asks Elmo if he would like to play "dress up" with her.

The puppet runs away instead, leaving Katy to chase him through a series of cartoon streets.

The pair sing new lyrics to Perry's song, including the lines: "Elmo's up Elmos' down, Elmo's running around / You're fast then you're slow, you're stop then you're go".

The episode is part of the 41st season of Sesame Street.