Japan on Tuesday lodged a diplomatic protest with China after Chinese and Russian naval vessels conducted joint live-fire exercises inside waters Tokyo claims as its exclusive economic zone (EEZ).
This marks the first time Japan has publicly disclosed such a drill in the area.
Japanese Defense Minister Shinjiro Koizumi said the Chinese and Russian navies held the exercise on Sunday about 180 kilometers (112 miles) southwest of Okinotorishima, a remote Pacific atoll that Japan regards as its southernmost island, according to Kyodo News.
Japanese top government spokesman Minoru Kihara confirmed it, telling reporters in Tokyo that the Japanese government has lodged a protest with China over the drills that could "endanger" nearby vessels.
According to Japan's Defense Ministry, a Chinese Type 052D guided-missile destroyer conducted machine-gun live-fire drills after issuing radio warnings, while Russian naval vessels participated in the joint exercise. Tokyo protested through diplomatic channels, saying the drill posed a risk to maritime and aviation safety.
China disputes Japan's claim that Okinotorishima qualifies as an island under international law, arguing it is merely a reef and therefore cannot generate an EEZ. Beijing maintains the exercise took place in international waters and did not violate international law.
Tokyo sees such drills a move as efforts to "strengthen military cooperation" between the Chinese and Russian militaries, said Kihara, adding that Tokyo continues to monitor the situation with "concern."
Speaking during a visit to the Farnborough International Airshow in Britain, Koizumi said the exercise reflected increasingly close military coordination between China and Russia and highlighted growing security challenges facing Japan, according to Kyodo.
The incident comes amid heightened tensions between Tokyo and Beijing over security issues, including Taiwan and China's expanding military activities around Japan's southwestern islands.
It also follows a series of joint Chinese-Russian naval and air patrols near Japanese territory in recent years, underscoring their deepening strategic partnership.
