SEOUL (Reuters) -South Korea's acting President Choi Sang-mok called on Monday to avoid any negative impact on science, technology and energy cooperation with the United States, after the U.S. Department of Energy (DOE) designated South Korea as a 'sensitive' country. The U.S. department has not explained why South Korea was added to the list, which can cause curbs on cooperation, though a DOE spokesperson said Seoul faced no new limits on bilateral cooperation in science and technology from the designation.