During the last few days, the Japanese government informed about a few incidents of near-violation of its early-warning defense zone.

On Tuesday, Japan's Joint Staff Office has informed that fighter planes of the Air Self-Defense Force Southwestern Air Defense Force responded to the likely intruder over the East China Sea.

On Jan 21 and 24, Japanese jets had to urgently act to prevent similar threats over the Sea of Japan, the Sea of Okhotsk, and the Pacific Ocean.

The Ministry of Defense and the Self-Defense Forces will continue to take all possible measures 24 hours a day, 365 days a year, to protect the peaceful lives of Japan's territory and its people, the author of the Join Staff Office said in the statement.

But it did not specify who was responsible for an intrusion.

During the joint drills of the Russian and Chinese army in December, the Russian airforce operated over the Sea of Okhotsk and the Sea of Japan, while the Chinese flew over the South China Sea.

Both armies have coordinated their flights over the Pacific Ocean in 2020 and 2021.