India, Japan and the United States on Monday conducted their first joint naval drills in the Pacific Ocean as the three try to forge closer ties, officials said.
Japan sent four escort vessels to the drill off Japan's east coast, where two US destroyers and three Indian warships joined the exercise, a Japanese defence ministry spokesman said.
"The first naval drill between Japan, the United States and India is aimed at boosting the friendly relationship among the three countries as well as improving maritime technique," the spokesman said.
The drill also looks at cooperation in the event of a major natural disaster such as a tsunami.
Japanese Prime Minister Shinzo Abe has repeatedly called for a four-way alliance among Japan, India, the United States and Australia to counter Tokyo's frequent tension with China.
Abe agreed to the naval exercises during a summit with his Indian counterpart Manmohan Singh in December.
Officials, however, have denied the drill is linked to China, whose Premier Wen Jiabao paid a landmark visit to Japan last week.
India has also been working to ease longstanding tensions with China.
The warships training with Japan and the United States were also scheduled to have joint exercises with China, Russia and Vietnam, according to the Indian defence ministry.