Tom Cruise's stunts in the new Mission: Impossible movie are "mind-blowing", says his co-star.

Tom has reprised his role as IMF operative Ethan Hunt for a fourth instalment of the action franchise.

In the film Mission: Impossible - Ghost Protocol, Tom insisted on performing a series of death-defying stunts. One sequence saw Tom dangling from the side of Dubai's Burj Khalifa the tallest building in the world.

His co-star Paula Patton admits she was terrified he could get hurt.

"He is doing that stunt, it was truly mind-blowing," she told ET. "One of the days he was doing this work on the side of building, I remember being in hair and make-up and going, Please, please don't let anything happen to Tom.' It was just so frightening to think of somebody hanging on the side of the building like that. It was wild."

It took months for Tom to perfect the impressive stunt.

He trained on a climbing wall so he could get to grips with scaling the 2,716 foot building for the movie.

"What they did first is they actually built walls for me just to practice my climbing and I would do drills to work out how we would do it. I spent months training," he explained. "I love making these movies. Ethan and his team get into these situations. I enjoy the challenge of coming up with these sequences."

In the new movie Ethan is blamed for the terrorist bombing of the Kremlin and his agency is shut down. He must track down the real bomber and discover the truth so he can save the Impossible Missions Force (IMF).

The film also stars Jeremy Renner and Simon Pegg. Tom had a great time on set with the cast and crew.

"I like to work with people that I like hanging out with, people that I admire that are really smart and talented so we can problem solve together," he added.

Mission: Impossible - Ghost Protocol is released worldwide this month.