Bradley Cooper says his ex-girlfriend Zoe Saldana is "incredible".

The actor is starring alongside the Avatar beauty in new movie The Words.

The stars dated during the filming process but reportedly split after only three months together.

However, Bradley has nothing but praise for his ex and credited her with bringing a new dimension to the romantic drama.

"Zoe's an incredible actor, [sic]" he told ET Online. "Actually, when she came on... the relationship [between their characters] was not as plot-driven as it became once she came on. So, we actually changed a lot of the major plot changes that occurred because of how committed [she was] and what truth she brought to the project."

Bradley also spoke about his close friendship with director Brian Klugman.

The two men have known each other since childhood and Brian helped Bradley to settle into Los Angeles when he first moved there.

Both have enjoyed success with their respective careers, and Bradley is thrilled that they got to make a movie together.

"We found a similar love for film [as children]... it was hard to find guys that loved film as maniacally as we did," Cooper reflected on their friendship. "He moved out to L.A. 18 years ago and I went out there as soon as I could and slept on his couch. So, the fact that we made a movie together is insane."