The U.S., Japanese and Indian navies have kicked off Malabar 2017 — and they are not holding anything back, reports The Diplomat. For the first time in the exercise's 25-year history, all three navies are bringing their largest vessels.

At least 17 ships and submarines from the three countries are expected to participate, including the carrier Nimitz, India's carrier Vikramaditya and Japan's warship Izumo, the largest Japanese ship since World War II, according to The Diplomat. The Nimitz is currently the largest carrier in the world, though the soon-to-be-commissioned carrier Gerald R. Ford will be larger.

The Bay of Bengal will play host to this year's Malabar, with training focusing on combating enemy submarines, according to a U.S. Navy release.

The U.S. and India have trained together each summer since 1992, while this is Japan’s third Malabar as a permanent member.

The timing of the training session carries extra significance as border disputes over where Bhutan stops and China begins have escalated between India and China in recent weeks, according to the South China Morning Post. China has accused India of crossing the border from Bhutan into China, while India insists it is still in Bhutan.

Malabar 2017 began on July 7 and is expected to last until July 17, according to the Navy.