Japan's Defense Ministry says Russian and Chinese naval vessels have navigated near the Izu Islands apparently as part of their joint patrol in the Pacific Ocean.

The ministry announced on Tuesday that three Chinese vessels, including a guided-missile destroyer, sailed between Sumisu and Tori islands on Monday.

The ministry also said four Russian vessels, including a frigate, passed through Japan's contiguous zone just outside territorial waters between Hachijo and Mikura islands on Tuesday.

This is the first time Russian naval vessels have sailed in these waters. All seven vessels headed west.

Officials have confirmed that six of the vessels fired machine guns in the Sea of Japan earlier this month.

They are believed to have taken part in Russia's Vostok large-scale military exercise.

After the exercise, Russia's defense ministry said Russian and Chinese ships started a joint patrol in the Pacific.

The two country's naval vessels sailed through Tsugaru Strait in northern Japan together for the first time in October last year and navigated around the Japanese archipelago.

Japanese defense officials continue to monitor their naval activities.