The recent establishment of China's air control zone that overlaps with those of South Korea and Japan has further aggravated conflicts in Northeast Asia, South Korean Foreign Minister Yun Byung-se said Wednesday. "China's Air Defense Identification Zone issue has made already tricky regional situations even more difficult to deal with," Yun made the remarks in his keynote speech at the defense forum in Seoul, according to Yonhap News Agency. "We've witnessed competition and conflicts among players of the region getting fiercer," he said. Tensions have been escalating since last Saturday when China announced the new air defense identification zone over the East China Sea that overlaps with those of South Korea and Japan. In response, South Korea and Japan expressed regret, and the US flew a pair of B-52 bombers through the area in defiance of the move. Yun, however, warned against having "unrealistic" concerns about the situation mirroring the past cold-war rivalry in the region, as "crisis management" is possible while seeking cooperation.