The defense chiefs of South Korea and Japan held bilateral talks in Tokyo on Sunday and discussed North Korea's evolving threats and ways to strengthen their cooperation, Seoul's defense ministry said.In their meeting, South Korean Defense Minister Shin Won-sik and his Japanese counterpart, Minoru Kihara, reaffirmed the importance of their bilateral and trilateral security cooperation, also involving the United States, in the face of North Korea's nuclear and missile threats and deepening military cooperation with Russia.They also agreed to draw up an annual plan for defense exchanges, including mutual visits and exchanges between the defense chiefs, top military officials and armed forces, as well as the resumption of joint search and rescue exercises, the ministry said in a release.Sunday's meeting marked the first visit by South Korea's defense chief to Japan's defense ministry in 15 years.Source: Yonhap News Agency