Gerard Butler has lavished praise on Irish actor Robert Sheehan saying "he is the best actor I've worked with in a long time."

The 47-year-old Scottish actor, who stars in new disaster movie Geostorm alongside Sheehan, couldn't speak highly enough of the Laois man.

Speaking to RTÉ Entertainment, Butler said"There’s nobody quite like Robert Sheehan. He’s so charismatic and he’s the best actor that I’ve worked with in a long time.

"Our director Dean [Devlin] fell in love with him and just put him as the lead in his next movie," he said.

Butler recalled how he turned to his manager during Geostorm's premiere at TCL Chinese Theatre in Hollywood to commend the former Love/Hate star for his acting chops.

"I was at the premiere of the movie the other night and I turned to my manager during the film and said ‘he’s so good!’.

"He’s just so in the moment and interesting and whenever he acts it doesn’t feel like he’s acting."

"He just as a way of keeping it very natural but entertaining and quirky at the same time," Butler added.

Butler plays a super-scientist/engineer in Geostorm who invents a fancy climate-controlling system that can halt global-warming. When the system malfunctions and starts to attack Earth, the brain behind the machine is tasked with saving the planet.

"At its central core it is a cautionary tale. I think when you see the opening it is kind of like a QuickTime version of this montage where you are seeing where we are going. It’s kind of a goosebump moment," he said.

"What I love about the idea behind that moment and the rest of the movie is ultimately what always defeat these forces are people coming together and then finally the governments get over all of their self interests and start working together to cure this larger problem. 

"But it’s also what happens personally with the characters and it’s about the scientific level. I think if people take anything from the movie it's that (1) Something needs to be done and (2) It is about us all coming together and actually doing something about it," he added.

Geostorm blows into cinemas nationwide on Friday, October 20.