Three Chinese navy ships have circumnavigated the Japanese archipelago over the past weeks, as Tokyo stays on alert for increasing military activity by Beijing and Moscow in nearby waters, Japan's Defense Ministry said Thursday.

Two guided-missile destroyers and a supply ship sailed through waters between Okinawa's main island and Miyako Island in southwest Japan and entered the East China Sea Thursday after circling around the country for about 20 days, and the ministry is analyzing China's intentions, according to the ministry's Joint Staff.

Photo taken on June 30, 2022, shows a Chinese navy's guided missile destroyer in the East China Sea. (Photo courtesy of the Japanese Defense Ministry's Joint Staff)(Kyodo)

Japan's Self-Defense Forces vessels and aircraft had kept a vigilant watch for the Chinese navy's flotilla, which was spotted sailing in the Sea of Japan after passing through the Tsushima Strait off Japan's southern island of Kyushu from June 12 to 13 and going around the archipelago clockwise, according to the Joint Staff.

Among the Chinese military's recent activities near Japan, fighter jets were seen taking off from and landing on the Chinese aircraft carrier Liaoning near the Okinawan islands for 12 days last month.

Japan's Defense Minister Nobuo Kishi also conveyed concern over a joint flight by Chinese and Russian strategic bombers in late May near Japan when he met with Chinese Defense Minister Wei Fenghe in Singapore earlier in the month.