American Sniper trailer: Bradley Cooper must make life or death decision

American Hustle actor plays deadly US Navy SEAL

(Warner Bros)

Clint Eastwood's American Sniper has debuted its first trailer, seeing Bradley Cooper play "the most lethal sniper in U.S. history".

Instead of the usual montage, the two-minute clip focuses in on one scene, as Cooper's character must decide whether to shoot dead an Iraqi woman and child who appear to be holding an RPG.

The movie is based on the autobiography of former US Navy SEAL Chris Kyle, who is regarded as the most deadly sniper in American military history.

Echoing the themes of Kathryn Bigelow's The Hurt Locker, American Sniper will focus on Kyle's harrowing tours of duty and his struggle to adapt to home life following them.

Sienna Miller co-stars as Kyle's wife Taya Renae, with Max Charles (The Amazing Spider-Man 2) and Luke Grimes (True Blood) also on the cast.

Eastwood won's Oscars for directing with Unforgiven and Million Dollar Baby and also garnered critical acclaims for films like Gran Torino and Changeling.

American Sniper has a 16 January release date.