Japan's annual diplomatic paper says the country's security environment is getting more challenging, vowing to strengthen the Japan-US military alliance. "The Diplomatic Bluebook 2016" said Japan will intensify cooperation with the US, and play a major role in forming the regional order. 

It also said Japan needs to protect navigation and flying freedom, citing its concerns over the South China Sea. Japan has become increasingly active in meddling affairs in the South China Sea. It also expressed "concern" in a statement issued at the G7 foreign ministers' meeting, which concluded recently in Hiroshima of Japan.