Sienna enjoys 'kicking butt' in new movie

Sienna Miller has admitted she is enjoying her role as a gun-wielding femme fatale in blockbuster G.I. Joe.

Miller plays The Baroness in Stephen Sommers's action film and has said that working on the movie has been "a lot of fun".

"It is really fun, and I get to really kick some butt.

"I am working out a lot and kickboxing and all that. But the best bit is that I'm doing that gun-twisting stuff. I am learning how to shoot properly and it's all cool and a lot of fun."

G.I. Joe is based on a series of comic books and a Hasbro toy line. The film will focus on the Global Integrated Joint Operating Entity, an organisation that faces off against Cobra, a terrorist group led by a Scottish arms dealer.

Dennis Quaid, Channing Tatum, and Joseph Gordon-Levitt are also among the cast. The film opens in August of next year.