Justin Bieber joins Jaden Smith for Karate Kid theme song

Justin Bieber has teamed up with Jaden Smith for the new Karate Kid theme song Never Say Never.

The track features Justin, 16, singing with Jaden, 11, performing backing vocals and a rap interlude. The video shows the pair in a recording studio eating red liquorice while watching clips from the movie.

Jaden, who has clearly inherited some of dad Will Smith's moves, shows off some body popping breakdance before launching into his solo.

The Karate Kid remake, which also stars Jackie Chan, opens June 11 in the US and July 16 in the UK.