A senior White House official has visited South Korea to discuss Beijing’s unilateral drawing of an air defense zone over the East China Sea, a government official here said Thursday.

Evan Medeiros, the senior director of Asian affairs at the National Security Council, was in Seoul on Wednesday and held talks with South Korean Vice Foreign Minister Kim Kyou-hyun and officials at the presidential office, ministry spokesperson Cho Tai-young told reporters.

While Cho said his visit was “to get prepared for the U.S. Vice President Joe Biden’s scheduled visit to South Korea next week,”

Seoul’s high-level official well-versed in the issue told Yonhap News Agency that Medeiros explained Washington’s stance on the air defense identification zone.

The U.S. official also expressed concerns that such a move will likely exert a negative influence on relations between the U.S. and China, as well as those with other countries in the region, a senior official added, requesting anonymity.

“Seoul also outlined its position on the ADIZ and its demand to Beijing to adjust it so as not to conflict with South Korea’s identification zone,” he said, adding that both sides concurred China’s latest move has posed serious challenges and agreed to work together on this issue.

China’s zone, announced over the weekend, overlaps South Korea’s zone, near Jejudo Island off the southern coast of the country. Seoul has already expressed regret over the overlap and said it wants to resolve this manner as soon as possible.

During the annual defense strategy talks on Thursday, Seoul demanded China redraw its ADIZ, but was turned down, escalating tensions between the two neighbors.

Medeiros, meanwhile, exchanged views on Seoul’s reservations about Japan’s moves to expand its right to exercise “collective self-defense,” which will allow Tokyo to conduct military exercises beyond its borders.

“The NSC official said Washington understood Seoul’s worries, but made clear Tokyo was within its rights to do so and that the United States supported such a move,” the source said.

After concluding his visit to Seoul, Medeiros flew to Japan to discuss similar issues, the source added. (Yonhap News)