Indonesia's navy said in a statement the routine Komodo drills were a "non-war" exercise that aims to "strengthen relationships between the navies" of 36 countries.

The drills come as China and the United States ramp up military diplomacy in the region, staging more frequent war games with allies and partners around Taiwan, and in the busy waterways of the South China Sea and the western Pacific.

The drills also follow a weekend incident in the Taiwan Strait in which the U.S. Navy said a Chinese warship cut in front of a U.S. destroyer in an "unsafe interaction".

Fifteen vessels, including from China and Russia, dropped anchor off Sulawesi island on Monday as the Komodo drills began, the Indonesian navy said.

The Chinese navy sent its destroyer Zhanjiang and frigate Xuchang, both equipped with guided missiles, to the exercise, Chinese state media CCTV reported on Monday.

This year's Komodo drills are the fourth such joint naval exercise Indonesia has hosted since the first one in 2014.

(Reporting by Stanley Widianto in Jakarta and Albee Zhang in Beijing; Editing by Kanupriya Kapoor and Tom Hogue)