TOKYO — The militaries of the United States and Japan began an enormous joint drill Monday, though leaving out a key part of the exercise that might have angered China.

Japan’s Defense Ministry said 37,000 Japanese and 10,000 American military personnel would be taking part in the 12-day drill, which involves U.S. Navy ships transporting Japanese troops. The top government spokesman, Chief Cabinet Secretary Osamu Fujimura, said the drill, near Okinawa, was not aimed at a specific country.

But the Japanese government canceled a joint amphibious landing on a remote island in what experts described as an effort not to provoke China, which is locked in an emotional dispute with Japan over control of uninhabited islands near Okinawa in the East China Sea.