Director Clint Eastwood has a new film coming out via limited release on Christmas Day that focuses on the life of a decorated Navy SEAL who suddenly died in 2013. Now it's being considered for an Oscar nomination.

American Sniper, based on Chris Kyle's 2012 memoir, showcases his overseas deployments that turned him into the deadliest marksman in U.S. military history. Bradley Cooper, the actor who portrays Kyle in the film, acquired the rights to the memoir before Kyle was tragically shot in early 2013 by a Marine veteran supposedly suffering from post-traumatic stress disorder; Cooper talked to NPR back on February 2013 on why such a film needed to be made.

"His story, first of all, needs to be told and it's also relevant on two fronts," Cooper said. "One, gun control, and two, the need to address this - the many soldiers that are coming back with post-traumatic stress disorder."

The movie trailer, which is available on YouTube, highlights how Kyle made difficult decisions in the fog of war. He is asking permission to take out a mother and child, who are armed with a Russian-made grenade and are headed toward a U.S. military convoy.

"They'll fry you if you're wrong," a fellow SEAL said to Kyle in the trailer.

Chris Lee of Entertainment Weekly noted that Kyle had 160 confirmed kills before retiring in 2009. British actress Sienna Miller, who portrays Kyle's wife, Taya, was asked whether or not Kyle's untimely death in 2013 made it in the final cut of the film.

"I'm not supposed to say anything," Miller said. "The film really focuses more on his life than on his death. That's what I'm supposed to say."

According to Entertainment Weekly, Cooper packed on pounds of muscle for the part and practiced alongside real Navy SEAL teams shooting live ammunition. As a film producer, Cooper promised Kyle "to do justice to his story."

"His performance is completely compelling. He's just unrecognizable," Miller said. "He was training four to six hours a day. He put on 40 pounds of muscle. He looked and sounded like a different person. I'm pretty sure he didn't break character for the entire thing. He dived into this completely head-first. It was an amazing thing to be around."

American Sniper shows how Kyle, through his overseas deployments, earned the nickname "Legend" thanks to his pinpoint accuracy and courage under fire. However, Lee noted that the film also follows Kyle's journey back at home in the civilian world.

"Ultimately, it is a war film," Miller said. "At the same time, you have romance: humanity grounded by a love story. The dilemma of life at home. Leaving that high-adrenaline, high-intensity situation behind and trying to be a father and husband."

Miller added that Kyle "is a man whose priorities in life are God, country, and family-in that order."

According to Entertainment Weekly, Warner Bros. will bring American Sniper to theaters in limited release on Dec. 25 and everywhere on Jan. 16, 2015.