NEW DELHI—The U.S., India and Japan will conduct joint naval exercises in the northern waters of the Philippine Sea, an area close to the East and South China Seas where Beijing is locked in an increasingly tense standoff with Washington.

The maneuvers are part of an annual event between the U.S. and Indian navies that, since 2014, has expanded to include Japan, signaling closer cooperation between the three countries that share concern about China’s military ambitions.

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