Willow and Jaden Smith have debuted a new song online.

The pair have teamed up for the track '5', which Willow uploaded recently to her Soundcloud page.

The effort is formally her tune, with Jaden Smith's vocals coming as part of a guest cameo.

The two siblings last collaborated on the track 'Kite', which was released by Jaden.

13-year-old Willow Smith shot to fame in 2010 when she unleashed the song 'Whip My Hair', which reached No.2 in the UK.

She has yet to release a full album, but she has featured on a number of singles.

Jaden Smith meanwhile has focused on acting, with the 15-year-old starring alongside his father Will in the 2013 movie After Earth.