India, United States, Japan and Australia began a naval exercise on Tuesday, the first of its kind in 13 years among the four major Indo-Pacific democracies that share concern over China's growing assertiveness in the region.
The annual Malabar exercise among the Quad members -- as they are collectively known -- is intended "to strengthen the relationship with friendly navies and to realize a free, open and inclusive Indo-Pacific," the Japanese Embassy in New Delhi said in a tweet.
The first phase is being held in the Bay of Bengal for four days, while a second phase is scheduled for mid-November in the Arabian Sea.
Malabar started in 1992 as a bilateral exercise between the Indian and U.S. navies. Japan joined in 2015.
This year marks its 24th iteration and features the Australian navy's participation for the first time since 2007.
Australian navy frigate Ballarat is joined by U.S. Navy destroyer John S. McCain, Japanese Maritime Self-Defense Force destroyer Onami and a number of Indian Navy ships, including destroyer Ranvijay, frigate Shivalik and submarine Sindhuraj.
Helicopters and other aircraft are also involved.
The four navies will practice a range of advanced warfare tactics, including air defense and anti-submarine exercises, with a focus on boosting interoperability, the U.S. Pacific Fleet said in a statement.
Without mentioning China by name, Australian Defense Minister Linda Reynolds said the four "regional defense partners" face shared challenges in the Indo-Pacific, so the imperative for them to cooperate closely is stronger than ever.
"Participation in sophisticated exercises like Malabar not only highlights the strategic trust between the members, but also strengthens our collective ability to contribute to regional security," she said in a statement.
Asked about the exercise recently, Chinese Foreign Ministry spokesman Zhao Lijian said, "China believes that military cooperation between countries should be conducive to regional peace and stability," without elaborating.
Australian, Indian, Japanese and American maritime forces routinely operate together in the Indo-Pacific, while the United States and India have also deepened defense cooperation in recent years.
Last year, the Malabar exercise was conducted off the coast of Japan, while it was held the previous year off the Guam in the Philippine Sea.
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