South Korea and Japan signed a military intelligence pact on Wednesday to share sensitive information on the threat posed by North Korea's missile and nuclear activities, the South's defence ministry said, according to Reuters. "Cooperation between Japan and South Korea is becoming more important than ever in the security sphere as North Korea's nuclear (development) and missiles pose a different level of threat from before," public broadcaster NHK quoted Japanese Foreign Minister Fumio Kishida as telling reporters in Miyagi Prefecture, northeastern Japan. "Signing of the pact has a very important significance." "This will add a new unsafe, unstable element for northeast Asia," ministry spokesman Geng Shuang told a daily news briefing. South Korea's Defence Minister Han Min-koo and Japan's ambassador to the South, Yasumasa Nagamine, inked the agreement in Seoul, according to the South Korean defence ministry.