North Korea has sentenced a Korean American man to 10 years' hard labour for subversion, China's Xinhua news agency reported.
Kim Dong-chul, 62, was arrested in North Korea in October and admitted to stealing military secrets and plotting subversion with South Koreans, the North's official news agency reported.
North Korea has in the past used detained Americans to extract high-profile visits from the United States, with which it has no formal diplomatic relations.
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Kim Dong-chul, who previously said he was a naturalised American citizen and was arrested in North Korea in October, admitted to committing "unpardonable espionage" under the direction of the US and South Korean governments and apologised for his crimes, the North's KCNA news agency said.
"The extraordinary crime I committed was defaming and insulting the republic's highest dignity and its system and spreading false propaganda aimed at breaking down its solidarity," the agency quoted him as saying.
Kim said that he was approached by South Korean intelligence officers in 2011 to engage in paid espionage, according to KCNA, adding that he was arrested while receiving a USB stick containing military and nuclear secrets from a source.
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A source in the North Korean capital of Pyongyang told the Reuters news agency that diplomats were notified in the morning of the confession and Kim's comments were similar to the recent confession of another American being held there, Otto Warmbier.
The US State Department said it was aware of the reported incident but had no further details, citing privacy concerns.
Warmbier was sentenced to 15 years hard labour this month for trying to steal a propaganda banner. The North is also holding a Korean-Canadian Christian pastor, who is serving a life sentence for subversion.
Photographs issued by the North's state news agency showed Kim bowing and wiping away tears.
North Korea faces the prospect of further international isolation after the United Nations Security Council imposed new sanctions after its fourth nuclear test in January and a long-range rocket launch in February.