While on set, Aaron Eckhart doesn’t care whether you like him or not, as his fellow cast members discovered to their detriment during the filming of his latest movie, Battle: Los Angeles.

“I was horrible. I was in character all the time and I pushed the cast because I wanted this movie to be real,” says 42-year-old Eckhart who stars as the fierce and tough-talking Marine Staff Sergeant Nantz in the mega-budget alien invasion film.

“Sometimes I got mad at them and sometimes they didn’t like me – that was hard. It can be a lonely feeling but you’ve got to do it for the sake of the film – and I think when they see it now, they appreciate it.”

When we meet Nantz, he’s a man on the brink of retirement tasked with training a new platoon to fight aliens after they begin attacking cities and threatening to extinguish all traces of life on Earth.

Visually-speaking, Battle: Los Angeles is a world away from Eckhart’s last movie Rabbit Hole, a low-budget drama in which he starred alongside Nicole Kidman as a grieving parent. But he says his personal goal always remains the same: for the audience to connect with the character.

“Battle: Los Angeles is an alien invasion movie, so first and foremost it’s entertainment,” says Eckhart. “For me it’s always about the acting and I took that very seriously. I wanted the audience not only to have fun, but also to feel.

“The actors have a responsibility to give everything we possibly can, to be as real as possible, or else we’ve short-changed them.”

And that, he emphasises, is irrespective of whether the film is an independent art-house or a mammoth popcorn movie.

“I like any genre of film as long as it’s based in reality and the actors believe what’s happening is real.

“If they don’t believe it, I won’t believe it – and that was important to me in Battle: Los Angeles.”

He thanks the movie’s director Jonathan Liebesman for remaining true to the initial vision of the film. Unusually Liebesman, with the help of Eckhart, put together a presentation reel to showcase his ideas to studio bosses.

“Jonathan didn’t have the job but we talked and he showed me a You Tube video of some marines going from house to house in Iraq and he said: ‘This is what I want the movie to look like’,” recalls Eckhart.

The pair, along with a few extras, then created a few minutes of raw footage they could use to tantalise studio execs.