Japan’s coast guard keeps watch on Chinese survey vessel near disputed islands

Japan coast guard vessels sail north of Uotsuri island, part of the Senkaku chain, in April 2024. (Ishigaki city, Okinawa)

Japan’s coast guard is monitoring a Chinese research vessel that has been conducting a survey in waters near the disputed Senkaku Islands since at least Monday afternoon.

The Chinese marine research vessel Xiang Yang Hong 22 was spotted about 40 miles west-northwest of Uotsuri Island, the largest of the Senkaku chain, at approximately 1:30 p.m. Monday, according to a coast guard news release that day.

Japan administers the islands, but China and Taiwan also claim them as their territory.

The research vessel remained in the area as of Tuesday afternoon, a coast guard spokesman said by phone. The coast guard is continuing to monitor the vessel and demands that it cease its activities, he added.

The vessel was observed on Monday extending pipe-like objects from both sides of its hull and wire-like objects from its stern into the ocean within Japan’s exclusive economic zone, which extends up to 200 nautical miles from a country’s baseline, according to the release.

A patrol vessel radioed the research vessel and stated that “scientific oceanographic research without Japan’s consent is unacceptable,” the release said.

The coast guard believes the vessel is conducting some kind of survey, although the exact purpose is unclear, the spokesman said.

Some Japanese government officials may speak to the press only on condition of anonymity.

Japan and China square off frequently over the five small, uninhabited islands and three reefs off Taiwan’s northeastern tip. Tokyo often accuses Beijing of harassing Japanese fishing boats there and sends its coast guard to intercede.

In October 2023, Japan lodged diplomatic protests with Beijing after a Chinese research vessel was spotted about 80 miles northeast of Taisho Island. It also appeared to be conducting a survey and had a wire-like object extended underwater from its stern, the coast guard said at the time.

In 2025, Chinese coast guard vessels entered Japanese territorial waters around the islands 27 times, the agency said. They also sailed in the contiguous zone around the Senkakus a record 357 times that year.

Tensions between Japan and China have risen in recent months. During a November parliamentary session, Japanese Prime Minister Sanae Takaichi said Tokyo could use military force if Beijing attacks Taiwan. Chinese President Xi Jinping has pledged to unify the democratic island with the mainland, by force if necessary.