United Kingdom, July 13 -- Matt Damon has admitted The Odyssey is "the hardest movie" he's ever made.

The Academy Award-winning actor plays Odysseus, the king of Ithaca, in the upcoming epic and while he was initially dismissive of director Sir Christopher Nolan's warnings about the scale of the task ahead, he quickly realised it was going to be a gruelling shoot.

Speaking on Sunday Sitdown with Willie Giest, Matt, 55, said: "[Nolan] was like, 'This movie's gonna be hard.' And I looked at him like, 'I've made, I don't know, 80 movies.'

"And he goes, 'No. This movie's gonna be really hard.' He, to his credit, was not lying.

"It was definitely the hardest movie I've ever done just because it was so ambitious, just because what he was tr...