China summoned Japanese and Philippine diplomats on Friday to express dissatisfaction over negative comments about it aired during a summit of the leaders of the United States, Japan and Philippines, the foreign ministry said. The United States and its allies, including Japan, have been building up their militaries to counter what they see as a growing threat from China in areas such as the busy waterway of the South China Sea and around Taiwan. At this week's summit in Washington, the three leaders discussed China's aggressive actions in the disputed South China Sea, besides unveiling a wide range of pacts to boost security and economic ties.