North Korea recently detained a U.S. citizen at Pyongyang's airport as he was about to leave the country, officials said on April 23.
South Korea's Yonhap News Agency, citing unnamed sources, said that the man, in his late 50s and identified by his surname, Kim, was doing aid work and was a former professor at the Yanbian University of Science and Technology in China.
The Swedish Embassy in Pyongyang said it was aware of the detention of a Korean-American citizen, but could not comment further.
The United States and North Korea do not have diplomatic relations, so the Swedish Embassy looks after consular affairs.
The reported arrest comes as tensions rise between Washington and Pyongyang over North Korea’s nuclear and missile programs.
At least two other Americans are currently detained in North Korea.