Prime Minister Fumio Kishida on Sunday criticized Beijing for stepping up actions that infringe on Japan's sovereignty in the East China Sea at an annual summit of the Association of Southeast Asian Nations and its partners.
The prime minister also delivered a warning to Russia against using nuclear weapons in its war on Ukraine.
The East Asia Summit, also attended by U.S. President Joe Biden, Chinese Premier Li Keqiang and Russian Foreign Minister Sergey Lavrov, took place amid tensions over Beijing's assertiveness in regional waters and pressure on Taiwan, while North Korea continues with a barrage of ballistic missile tests.