Justin Bieber has been chasing a duet with Cheryl Cole for "over a year".

The 'Baby' singer has called Cheryl "beautiful" and flirted with her when he performed on British TV show 'The X Factor' - on which she was a judge - in 2010, and her manager, will.i.am is hoping they will soon appear on record together.

will.i.am said: "I am very tight with Justin's mentor, Usher, and Cheryl has met him as well. We are like one tight little family and there is a lot of potentially exciting stuff in the pipeline.

"Justin is a big fan of Cheryl and has been asking Usher if he can set something up with her for over a year now."

william also described how Cheryl is working with top producers and stars for her third album, which he believes will make her a huge star in the US.

He added to heat magazine: "This album is going to be the best material she has ever released. Some of the biggest names in the industry are working with her. When Cheryl is happiest she is infectious, and this is the happiest she has been in a long time.

"Will she break the US? When people meet Cheryl for the first time they want to meet her again because she is just great company. So the answer to your question is yes, without a doubt."