North Korea's Supreme Court sentenced a U.S. student to 15 years in prison with hard labor Wednesday for crimes against the reclusive Asian state, according to reports. Otto Frederick Warmbier, an undergraduate student at the University of Virginia, was arrested in early January for attempting to steal a propaganda banner from a staff-only section of the hotel he was staying at in Pyongyang.

Warmbier was charged with subversion and sentenced after an hour-long trial in the court, the Associated Press reported. The 21-year-old had confessed and apologized to the crime in February.

At a press conference held last month in North Korea's capital city, Pyongyang, Warmbier said he tried to take the banner as a trophy from the Yanggakdo International Hotel for an Ohio church member who promised him a used car worth $10,000. The member had also promised to give Warmbier’s mother some $200,000 in case he was arrested and could not go home. The Wyoming, Ohio, native said that he accepted the offer because his family was “suffering from very severe financial difficulties.”

Otto Warmbier Otto Frederick Warmbier, a University of Virginia student detained in North Korea since early January, attends a news conference in Pyongyang, North Korea, in this photo released by Kyodo News, Feb. 29, 2016. Photo: REUTERS/Kyodo

“I entirely beg you, the people and government of the DPRK [Democratic People’s Republic of Korea], for your forgiveness. Please! I made the worst mistake of my life,” he said at the press conference.

After Warmbier’s arrest, North Korea said that he committed an anti-state crime with “the tacit connivance of the U.S. government and under its manipulation.”

Pyongyang has consistently accused the U.S. and South Korea of sending spies to North Korea to oust the Kim Jong Un-led regime so as to allow Seoul — backed by Washington — to take control of the Korean Peninsula.

Most tourists visiting North Korea are Chinese but North Korea also reportedly draws in about 6,000 people from Western countries annually. Pyongyang has been known to detain several tourists from Western countries on charges of spying and the U.S. State Department strongly recommends its citizens against traveling to North Korea.