Matt Damon "almost started crying" when he found out "last fall" that George Clooney is set to become a father.

Matt Damon

Matt Damon

The 'Great Wall' star admits his close friend, whose wife Amal Clooney will give birth to twins in June, shared the happy news with him when the human rights lawyer was just eight weeks into her pregnancy.

The Oscar winner told 'Entertainment Tonight Canada': "I was working with him last fall and he pulled me aside on set and I mean, I almost started crying. I was so happy for him. And I was like, 'How far along is she?' And he goes, 'Eight weeks.'"

Matt, who has four daughters with wife Luciana Barroso, scolded George, 55, for telling him the news before Amal had entered her second trimester.

He said: "(I said) 'Are you out of your mind?! Don't tell anybody else! Don't tell anybody else! Don't you know the 12-week rule?' Like of course he doesn't. 'Just shut up, man.' And then four weeks later, I'm like, 'We're good right?' (George confirmed) 'We're good.'"

The 46-year-old star thinks George is very lucky to have found Amal, 39, and predicts they'll be great parents.

He added: "So yeah, I'm thrilled for him. She's amazing. He hit the jackpot. Just on every level. She is a remarkable woman. They're gonna be great. They're gonna be awesome parents. Those kids are lucky."

The couple have yet to officially comment on the news, but confirmed the rumours they're expecting twins through multiple friends.