North Korea says it has detained third U.S. citizen for 'hostile' acts

May 3 (UPI) -- North Korea confirmed it has detained a third U.S. citizen – a move analysts describe as Pyongyang's way of increasing the number of bargaining chips for future negotiations with the United States.

Pyongyang's state-controlled news agency KCNA reported an American of Korean heritage, Tony Kim aka Kim Sang Duk, was detained on April 22.

He is being charged with "hostile acts" against the Kim Jong Un regime, but the statement from North Korea did not elaborate on his alleged crimes.

"During his time in our country, U.S. citizen Kim Sang Duk attempted to overthrow the state, a hostile crime. According to our laws, he was arrested at Pyongyang International Airport at 8 a.m., April 22," the statement read, but provided no further information on his actions.

Kim was teaching accounting as a visiting professor at the Pyongyang University of Science and Technology, a school that opened in 2010 as the first privately funded institution in North Korea.

In 2014, the school was the subject of a BBC documentary, when North Korea permitted access to students and their daily environment.

But as tensions have grown between the United States and North Korea, Pyongyang has also been detaining tourists and visitors on civic exchange.

Other Americans in North Korea detention include Otto Warmbier, the University of Virginia student who was sentenced to 15 years of hard labor for removing a political banner, and Kim Dong Chul, a businessman who was arrested on spying charges in 2015.

PUST has been facing financial difficulties because of a lack of South Korea funding, which has been dwindling as relations have worsened with Seoul.

Former U.S. Ambassador to China Gary Locke said North Korea was looking for "bargaining chips" for future negotiations with the United States, CNN reported.