The Black Eyed Peas star is a huge fan of the 'Sorry' singer and thinks he is a very influential performer, reported Female First.
"I've always believed in that kid, I think he's extremely talented and I'm happy for him. It's one thing to have success, and it's another to be paving the way and defining contemporary pop music. He went underground and took underground to the surface, so hats off," Will i am said.
He added other people weren't always convinced by his faith in the 21-year-old singer, both at the beginning of his career and again a few years ago when Bieber's wild partying and bad behaviour were generating more headlines than his music.