The US energy department put South Korea on a watchlist because visitors to its laboratories mishandled sensitive information, Joseph Yun, the acting US ambassador, said on Tuesday.

The U.S. government’s move to put South Korea — a nonnuclear ally — in the same company as countries like China or North Korea has unsettled politicians in Seoul

South Korea's acting president urged ministries on Monday to work with the U.S. to avoid any negative impact on science, technology and energy cooperation after the U.S. Department of Energy designated South Korea a 'sensitive' country.