Warmbier, a 21 year old University of Virginia student, was detained by the North in January for trying to steal an item bearing a propaganda slogan from his hotel in Pyongyang and had confessed to crimes against the state, North Korean media said previously.
He was convicted and sentenced in a one-hour trial at the North’s Supreme Court.
Warmbier was arrested as he tried to leave the country in early January.
In a statement made before his trial, he told a gathering of reporters in Pyongyang he tried to take the banner with a political slogan on it as a trophy for the mother of a friend.