North Korea confirmed Friday that it had arrested a US citizen in November, saying he had admitted to unspecified charges and suggesting he would be formally prosecuted.
The man, identified as Pae Jun-Ho, entered the North on November 3 as a tourist, and "committed a crime" against the country, the official Korean Central News Agency (KCNA) said.
"He was put into custody by a relevant institution," it added.
The United States has no diplomatic ties with North Korea and KCNA said consular officials from the Swedish embassy, which acts on behalf of the US, had visited Pae on Friday.
"In the process of investigation, evidence proving that he committed a crime against the DPRK (Democratic People's Republic of Korea -- the North's official name) was revealed. He admitted his crime," the agency said in a short dispatch.
"Legal actions are being taken against Pae in line with the criminal procedure law", it added, without elaborating.
State Department spokesman Patrick Ventrell confirmed that a US citizen had been detained in North Korea.
"The embassy of Sweden, which is our protecting power in Pyongyang, has been granted consular access and is providing all appropriate consular assistance," he said.
"But because of privacy considerations, that's the extent that we can say on this matter right now.
The arrest was first reported earlier this month by a South Korean newspaper, Kookmin Ilbo, which had identified the detainee as a 44-year-old Korean-American tour operator.
The newspaper said he had been travelling with five other tourists and was detained when a computer hard disk was found among the group's belongings.
KCNA said Pae was arrested as he entered the northeastern port city of Rason, which lies inside a special economic zone near North Korea's border with Russia and China.
Several Americans have been held in North Korea in recent years.
In 2011, a US delegation led by Robert King, the special envoy for North Korean human rights issues, secured the release of Eddie Jun Yong-Su, a California-based businessman, detained for apparent missionary activities.
In 2010 former US president Jimmy Carter won plaudits when he negotiated the release of American national Aijalon Mahli Gomes, sentenced to eight years of hard labour for illegally crossing into the North from China.
On another mercy mission a year earlier in 2009, former president Bill Clinton won the release of US television journalists Laura Ling and Euna Lee, jailed after wandering across the North Korean border with China.