United Kingdom, Sept. 18 -- Josh Duhamel has praised ex-wife Fergie as an "amazing mom".

The 52-year-old actor has Axl, 12, with the Black Eyed Peas star and 20-month-old Shepherd with "amazing wife" Audra Mari and admitted they all need to work together for the sake of their kids, particularly when he's far away filming as he was with latest movie London Calling, which was shot in South Africa.

He told Us Weekly magazine: "We all have to work together to make sure that this thing works.

"if you're in Vancouver or New Mexico, it's one thing. But when you're in Cape Town, there's no going back and forth on the weekends," he explained. "You're either there you're not. So it's a struggle."

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