Kristen Stewart has spoken for the first time about her lesbian kiss with Dakota Fanning in the pair's new movie, The Runaways.

The 19-year-old Twilight star, who is normally seen on screen locking lips with Robert Pattinson, said she was wasn't intimated by the prospect of kissing Dakota.

"It's just something we did," she told E! Online.

"In this story, it's so not like a romantic thing. It's just something that they just do."

Speaking at the Sundance Film Festival premiere of the Joan Jett biopic, Kristen admitted that the kiss was one of a number of challenges in the film.

"We had so many other really crazy things that we were intimidated by, like, we had a performance that day, so when that came up on the schedule we were like, 'Whoa!',” she said.

"But then, 'Alright, whatever'. It was sort of just like another thing."

The Runaways is due to be released in March. You can see exclusive stills here.

Kristen Stewart and Robert Pattinson