Pharrell Williams believes Ed Sheeran is a "genius".

The US superstar producer teamed up with the Brit on the singer-songwriter's new single 'Sing'.

He features in the video for the song and it seems Williams had a blast on set.

He took to Twitter to say alongside a link to the clip: "Loved working with @edsheeran on Sing. He's a genius."

Sheeran replied in a humble fashion, saying: "Likewise dude. See you soon!"

'Sing' is due to feature on the Brit's upcoming album 'x', which is slated for a UK release of June 23.

The record marks the follow-up to Sheeran's 2011 debut '+', which spawned the hit singles 'Lego House' and 'The A Team'.

Watch the 'Sing' video below: