The American student, tearfully apologised for trying to steal a political propaganda poster in his hotel in Pyongyang, the North Korean capital, last month. He was sentenced for subversion on Wednesday, news agencies reported. American student Otto Warmbier, 21, leaves the Supreme Court in Pyongyang on Wednesday. Credit:AP Otto Warmbier, 21, a University of Virginia undergraduate from Cincinnati, was convicted after a one-hour trial at the country's Supreme Court, according to The Associated Press, which has a bureau in Pyongyang. The Japanese news agency Kyodo and the Chinese state-run Xinhua news agency also covered the conviction and sentencing. The sentence is the latest penalty that North Korea has meted out to a small number of American tourists, missionaries and journalists in recent years for what have been deemed anti-state crimes, including accusations of illegal entry and leaving a Bible behind in a hotel. Warmbier, who entered North Korea as part of a tour group, was detained on January 2 as he was about to board a plane to leave the country. In announcing his arrest, the state news media said Warmbier had visited with the intent of "bringing down the foundation of its single-minded unity."

The charges against him claimed that the CIA, a secretive American university organisation and a member of a church in Ohio had encouraged him to commit the "hostile act" of stealing a political poster from a wall in his hotel. American student Otto Warmbier, 21, was sentenced to 15 years hard labour. Credit:AP In late February, Warmbier sobbed and pleaded for his release at a government-arranged news conference in Pyongyang, where he admitted to stealing the poster and said that the church member had offered to buy him a used car worth $10,000 in exchange. "I made the worst mistake of my life," Warmbier said. A video clip posted on CNN correspondent Will Ripley's Twitter account showed a sobbing Warmbier saying: "I have made the worst mistake of my life, but please act to save me." He said a "deaconess" had offered him a used car worth $US10,000 ($14,000) if he could present a US church with the slogan as a trophy from North Korea.

The acquaintance also said the church would pay his mother $US200,000 ($280,000) if he was detained by the North and did not return, KCNA quoted Warmbier as saying. "My crime is very severe and pre-planned," Warmbier was quoted as saying, adding that he was impressed by North Korea's "humanitarian treatment of severe criminals like myself". It was impossible to determine whether Warmbier had been coerced into making the statements. Some American detainees who have spoken at similar news conferences in Pyongyang later said, after being freed, that they had been forced to confess to crimes and to apologise. Former Governor Bill Richardson of New Mexico, a veteran diplomat and North Korea troubleshooter, met with two North Korean diplomats from the United Nations on Tuesday to press for Warmbier's release.

Richardson said the meeting, at a hotel near the UN headquarters in New York, was his first face-to-face dealing with the North Koreans since he was asked by Governor John Kasich of Ohio to get involved in the case. "I urged the humanitarian release of Otto, and they agreed to convey our request," Richardson said by telephone afterward. He also said the diplomats, Ambassador Jang Il Hun and a subordinate, confirmed that Warmbier had been seen in Pyongyang, the North's capital, by a diplomat from Sweden, which represents the United States' interests in North Korea. The imprisonment of Warmbier, if confirmed, would further chill relations with the US as the Obama administration seeks to ratchet up pressure on the regime in Pyongyang over a fourth nuclear test in January and a long-range rocket launch weeks later. The United Nations Security Council this month passed a resolution tightening sanctions on North Korea, including a ban on exports of certain minerals - a key source of hard currency for the Kim Jong Un regime.

US President Barack Obama approved slapped new sanctions on Kim Jong-un's regime on Wednesday. He issued an executive order imposing "robust new sanctions" on North Korea, aimed at stopping North Korea's nuclear and ballistic missile programs. The sanctions ban the export of certain minerals from the country, prohibits the sale of luxury items to North Korea, and imposes travel bans and asset freezes. North Korea has used detained and convicted US nationals as a way to draw prominent American figures such as former US president Jimmy Carter into Pyongyang as mediators to open negotiations with Washington. The US' efforts to help Warmbier are complicated by having no diplomatic relations with North Korea. Instead, it maintains contact through the Swedish embassy in Pyongyang.

US citizens in North Korea have sometimes been used as a tool to put pressure on the US government, analysts say, with North Korea forcing visits by high-level officials or former leaders to secure the release of the detainees. James Clapper, director of national intelligence, went to North Korea in November 2014 to gain the release of two Americans. He returned with Kenneth Bae, then a 46-year-old Korean-American missionary, who had been sentenced to 15 years of hard labour after North Korea convicted him of proselytising, and Matthew Todd Miller, a 25-year-old American who was charged with "unruly behaviour" after he tore up his passport and for trying to infiltrate the country's prison camps. Former president Jimmy Carter travelled to North Korea to win the release of Aijalon Mahli Gomes, an American accused of illegally entering the country in 2010, and former president Bill Clinton went to North Korea to secure the release of journalists Laura Ling and Euna Lee in 2009. Bloomberg, New York Times