Japanese Defense Minister Taro Kono  (Photo: CNN)

Beijing's efforts at transforming obscure sandbars and reefs into a string of highly fortified artificial islands stretching hundreds of miles across the South China Sea does not promote or uphold the international order, the defense minister said.

He added China’s missile batteries and deployments of fighter jets and bombers on several of the newly created islands is destabilizing. Kono said a free and open maritime order in the South China Sea is as important as any other place and what happens there will concern the international community.

Japan has also been concerned about China’s infiltration into the East China Sea, saying China’s acts violate international law.