US podcaster Joe Rogan was filming the latest episode of his show with actor Charlie Sheen when news broke that conservative activist Charlie Kirk had been shot dead.

The pair’s shocked reaction was caught live on camera as they were told of the shooting by a producer.

“This has just happened. We just got word that Charlie Kirk got shot,” the podcast host said, looking stunned and clutching at his head.

“That’s f—ing awful,” Sheen, 60, said in the video.

“Murdered for having a different opinion from somebody else. A different ideology from somebody else.”

Rogan responded by saying they didn’t know who had killed the 31-year-old Turning Point USA creator and Donald Trump ally, or what their motivation was.

The podcaster never interviewed Kirk on his show, but said he had met him once at a gun range.

“He’s not a violent guy,” Rogan said. 

“He was talking to people on college campuses.”

He added that Kirk “wasn’t even particularly rude. He tried to be pretty reasonable with people.”

Rogan lamented that the US was a country where people were deeply at odds with each other.

“People are so divided in this country… and there’s so many people that love it and they profit off that division.”

“One of two things is going to happen,  people are going to realise how f—ing insane this is…. or it’s going to get a lot worse.”

Kirk, a married father-of-two, was killed on Wednesday afternoon local time as he was speaking on stage to a crowd at Utah Valley University campus.

The killer, who fired the fatal shot from atop a nearby building, is still on the run.