North Korea's official KCNA state news agency reported on Friday that the man was detained on April 10, after tearing up his visa while entering the country. The man was identified as 24-year-old Miller Matthew Todd - possibly putting his surname first.

"A relevant organ of the DPRK put in custody American Miller Matthew Todd, 24, on April 10 for his rash behavior in the course of going through formalities for entry into the DPRK to tour it," KCNA said, using the country's official name, the Democratic People's Republic of Korea.

The report said the detained man had a tourist visa to enter the country, but tore it up and shouted he had come to North Korea "after choosing it as a shelter." KCNA said the man was detained for "gross violation" of the country's legal order and was being investigated.

No confirmation from US

US State Department spokeswoman Jen Psaki told reporters in Washington on Friday that the US was aware of the reports, but would not confirm an American was being held in North Korea.

Psaki said the department was in touch with the Swedish embassy in Pyongyang over the issue. Sweden represents the interests of US citizens in North Korea as Washington does not have any diplomatic relations with the country.

"There is no greater priority to us than the welfare and safety of US citizens. We don't have additional information to share at this time," Psaki said.

Obama in South Korea

Friday's announcement came during US President Barack Obama's visit to South Korea, one of Washington's closest allies which is technically still at war with its northern neighbor.

North Korea has held a Korean-American missionary, Kenneth Bae, since November 2012. He was arrested after leading a tour group in the country and sentenced to 15 years of hard labor on charges of state subversion.

Pyongyang has twice cancelled visits by the US special envoy for North Korean human rights issues, Robert King, to discuss Bae's case.

In February, North Korea freed John Short, a 75-year-old Australian missionary accused of distributing Bible text at a Buddhist temple in Pyongyang, on what was the birthday of deceased leader Kim Jong Il.

Korean War veteran Merrill Newman, 85, was freed from custody in December, after his arrest in October in Pyongyang while boarding a plane back to the US after a tourist visit. .

jr/slk (Reuters, AP)