Washington (CNN) -- The North Korean government informed the State Department on Friday that it is holding a second American citizen who the North Koreans say entered the country from China, a State Department spokesman said.
The American, who has not been identified, was detained Monday for trespassing on North Korea's border with China, state-run Korea Central News Agency reported Thursday. The incident is under investigation, according to the agency's report.
Spokesman P.J. Crowley had said Thursday afternoon that the department had been unable to get information on the reported incident.
North Korea announced December 29 that it was holding an American who had entered the country illegally from China on Christmas Eve. The news agency did not identify the man, who it said was "now under investigation by a relevant organ."
At the time, State Department spokesman Ian Kelly said Washington was concerned by reports that a Korean-American missionary, Robert Park, had gone into North Korea, but could not confirm them.
Washington and Pyongyang have no diplomatic relations. The United States relies on the Swedish Embassy to look after U.S. interests in North Korea.
Crowley has said the United States continues to seek consular access to Park.