CNN—North Korea has sentenced American student Otto Frederick Warmbier to 15 years hard labor for crimes against the state, a North Korean official confirmed to CNN Wednesday. Warmbier had traveled to Pyongyang on a trip organized by Young Pioneer Tours, a China-based travel company. He was arrested on January 2, 2016, as he was about to board a plane to leave the country In an emotional press conference last month, the 21-year-old student at the University of Virginia admitted to attempting to steal a banner with a political slogan from his hotel in the North Korean capital. It is not known whether Warmbier made the admission under duress. U.S. says North Korean submarine missing Appearing to read from a statement, he said: "I committed the crime of taking down a political slogan from the staff holding area of the Yanggakdo International Hotel." Warmbier is escorted at the North Korean Supreme Court on Wednesday, March 16, 2016. "I never, never should have allowed myself to be lured by the United States administration to commit a crime in this country," he said tearfully, as he begged for forgiveness. "I wish that the United States administration never manipulate people like myself in the future to commit crimes against foreign countries. I entirely beg you, the people and government of the DPRK, for your forgiveness. Please! I made the worst mistake of my life!" Warmbier tearfully confessed to "hostile acts" against the DPRK The North Korean government alleges Warmbier was encouraged to commit the "hostile act" by a purported member of an Ohio church, a secretive university organization and even the CIA. The tour company he traveled with said on its website it is aware of his sentencing and that it should "be viewed in similar context of previous cases of Americans being sentenced in the DPRK." North Korea threatens nuclear strike over U.S.-South Korean exercises Kenneth Bae and Matthew Miller are the most recent American detainees who have been released by North Korea. Both were accused of perpetrating "hostile acts" against North Korea; Miller spent less than a year in custody after being sentenced to six years hard labor, and Bae, facing a 15-year sentence, was held for nearly two years. The pair secured their freedom in late 2014. Former New Mexico Gov. Bill Richardson told The New York Times he met with two North Korean diplomats on Tuesday to lobby for Warmbier's release. Richardson is a veteran diplomat and a former U.S. ambassador to the United Nations. Tensions have been particularly fraught on the Korean peninsula in recent weeks. Some North Korea watchers have accused the regime of using detained U.S. citizens as political pawns.