Chinese warships cross waters near Japan island

Asked how China sees the reported scenario, Chinese Foreign Ministry spokesman Hong Lei said, "To maintain the peace and stability of Asia-Pacific is beneficial to all sides." He added: "Increasing tension is against the bigger trends of regional security, peace and the buildup of political and security trust. We reserve the right to take further action."

Defense Minister Morimoto declined to confirm the scenario or give other details.

In Sunday's exercise, about 40 ships — including state-of-the-art destroyers, hovercraft able to launch assaults on rough coastlines and new conventionally powered submarines — took part in Fleet Review 2012, the maritime equivalent of a military parade.

About 30 naval aircraft, mostly helicopters, also participated. For the first time, Japan's navy was joined by warships from the United States, Singapore and Australia. Representatives from more than 20 countries, including China, attended the event staged in waters south of Tokyo.

Associated Press writers Ian Mader in Beijing and Mari Yamaguchi in Tokyo contributed to this report.