North Korea confirmed Wednesday that it has detained an American professor who was seized April 22 at Pyongyang International Airport as he tried to leave the country.
The Korean Central News Agency says Kim Sang Dok, whose American name is Tony Kim, is accused of attempting to overthrow the government of the North's authoritarian leader, Kim Jong Un.
"He was intercepted for committing criminal acts of hostility aimed to overturn the DPRK not only in the past but also during his last stay before interception," KCNA said. DPRK is the acronym for the Democratic People's Republic of Korea.
Relations between the U.S. and North Korea have grown more strained in recent months as Pyongyang has continued to conduct nuclear and ballistic missile testing in defiance of international bans. North Korea's leader in turn has expressed outrage at massive joint military exercises conducted by the U.S. and South Korea.
Then, on Sunday, President Trump said he would be "honored" to meet North Korean's leader "under the right conditions." He called Kim a "smart cookie" for seizing and retaining power after the death of his father, Kim Jong Il, in 2011.
The investigation into Tony Kim, one of at least three Americans being held by Pyongyang, is ongoing, KCNA said. Pyongyang University of Science and Technology issued a statement last week saying he was arrested after "several weeks of service" teaching accounting at the school.
"We understand that this detention is related to an investigation into matters that are not connected in any way with the work of PUST," the school said.
The school is the only privately funded university in North Korea. It opened less than a decade ago and is unique for its large number of foreign staff.
Kim previously taught at Yanbian University of Science and Technology in China, near the Korean border. It is rare for Americans to travel to Pyongyang, but China is North Korea's closes ally and travel between the two nations is common.
The U.S. State Department had no comment Wednesday on Kim's detention, citing privacy concerns. Last week, the department issued a statement saying it was aware of the media reports. The U.S., however, has no embassy or consulate in North Korea.
"The protection of U.S. citizens is one of the Department's highest priorities," the department said in a statement. "In cases where U.S. citizens are reported to be detained in North Korea, we work with the Swedish Embassy, which serves as the United States' Protecting Power in North Korea."
At least two other Americans, Kim Dong Chul and Otto Warmbier, are being held by North Korea.
Warmbier, a University of Virginia student, was arrested in January 2016 while on a tour of North Korea. He was accused of committing a "hostile act" for allegedly trying to steal a political banner and was sentenced in March 2016 to 15 years hard labor.
Kim Dong Chul was arrested in October 2015 while in North Korea on business. He was accused of stealing military secrets and is serving a 10-year sentence.