The US State Department has confirmed reports that an American citizen has been arrested in North Korea.
On Friday, North Korea declared it had arrested an American student from the University of Virginia for "perpetrating a hostile act" against the government.
North Korea's official Korean Central News Agency reported that the 21-year-old student, identified as Otto Frederick Warmbier, had traveled to the North as a tourist but "for the purpose of bringing down the foundation of its single-minded unity at the tacit connivance of the US government and under its manipulation.”
He was detained "while perpetrating a hostile act against the DPRK,” the report said.
Speaking in Davos, Switzerland, US State Department spokesman John Kirby said on Friday, "The welfare of US citizens is one of the department's highest priorities."
Kirby said in such cases the US works closely with the Swedish embassy in Pyongyang which assists Washington in North Korea.
He however refused to release further information, citing "privacy considerations."
Several Americans have been held in North Korea in recent years.
In October last year, North Korea freed a South Korean national with a US green card after holding him for six months. Also in 2014, Pyongyang released three detained Americans.
The developments come as tensions are currently running high on the Korean peninsula. The US, and with allies Japan and South Korea have led calls for a tough UN Security Council resolution in the wake of a January 6 nuclear test by North Korea.
North Korea accuses the US of plotting with regional allies to topple its government. Pyongyang says it will not relinquish its nuclear deterrence unless the US ends its hostile policy toward it and dissolves the US-led UN command in the region.