North Korea's Supreme Court has sentenced Matthew Miller, a U.S. citizen, to six years with labour for entering the country illegally and trying to commit an act of espionage.

The court said Sunday that the 24-year-old Miller, of Bakersfield, Calif., tore up his tourist visa at Pyongyang's airport when he entered the country on April 10 and intended to "experience prison life so that he could investigate the human rights situation."

In a short statement carried by state media, North Korean officials said Miller "committed acts hostile to the DPRK while entering the territory of the DPRK under the guise of a tourist," Reuters reported.

After its brief session Sunday morning, the court denied Miller any appeal.

Reuters reported that photos of the trial released by state media showed some of Miller's personal possessions, including his passport and North Korean visa, which was ripped. Miller was also shown sitting in a witness box, flanked by North Korean soldiers.

A trial is also expected soon for 56-year-old Jeffrey Fowle, who entered the North as a tourist but was arrested in May for leaving a Bible at a provincial club.

A third American, Korean-American missionary Kenneth Bae, is serving out a 15-year sentence for alleged "hostile acts."