State news agency KCNA identified him as University of Virginia student Otto Frederick Warmbier.
He had entered North Korea as a tourist with the intention "to destroy the country's unity", said KCNA, which added that the US government had "tolerated and manipulated" him. It did not give further details, but said he was now under investigation. The US State Department is "aware of media reports that a US citizen was detained in North Korea" and is working with its protecting power, the Swedish Embassy in Pyongyang, Deputy Spokesperson Mark Toner said. He said that no further information would be shared at this time due to privacy concerns. North Korea sometimes uses the detention of foreigners as a means of exerting pressure on its adversaries.