Cameras have captured the awkward moment when Hollywood actor George Clooney learnt of the divorce between his friends Brad Pitt and Angelina Jolie.

Clooney, 55, was attending an event at the UN headquarters in New York as part of the UNHCR refugee summit, when a CNN reporter inadvertently revealed the news, assuming he had already heard.

“All right, don’t shoot me on this last question. It’s a big story, you’re friends with both of them. Your thoughts, any thoughts?” the reporter asked.

George Clooney was at a UN event, when a CNN reporter revealed the news.

George Clooney was at a UN event, when a CNN reporter revealed the news.

After it became apparent that Clooney had no idea what had happened to his Oceans Eleven co-star, the reporter dropped the news: “Divorce. She filed.”

“I didn’t know that,” a stammering Clooney replied. “That’s … wow. I feel very sorry [for them], then.”

Noticeably taken off guard, the actor added that it was the first he had heard of the divorce.

“That’s a sad story, then. That’s unfortunate for a family … That’s an unfortunate story about a family. I feel very sorry to hear that.”

Pitt and Jolie announced their separation on Tuesday night, after TMZ obtained court documents which showed she had filed for divorce from Pitt after a 12-year romance.

According to reports, Pitt’s ex-wife Jennifer Aniston has commented on the split, with a source telling Us Weekly she said “that’s karma for you”.

Pitt and Jolie got together in 2005 after meeting on the set of 2003 action-comedy film Mr and Mrs Smith.

The couple married in 2014 in front of their six children.

Clooney and Pitt are long-time friends.

In March, Clooney revealed the pair were in the thick of a “prank war”, saying he had purchased a special gift for Pitt after he started driving a Toyota Prius.

“I got a bumper sticker in the shape of a pot plant, that said, ‘F… cops,’ and I put that on the back of his car,” Clooney said onstage at the Adobe Summit. “Because there’s no way you’re not getting arrested with that.”