Russian and Chinese warships have held their first joint patrols in the western part of the Pacific Ocean.
Russia's defence ministry released a statement on Saturday saying that exercises between the two nations were conducted between October 17 and 23.
Moscow and Beijing had staged naval cooperation drills in the Sea of Japan earlier in October.
They have cultivated closer military and diplomatic ties in recent years at a time when their relations with the West have soured.
The naval manoeuvres have been closely watched by Japan.
It said earlier this week that a group of 10 vessels from China and Russia sailed through the Tsugaru Strait separating Japan's main island and its northern island of Hokkaido.
This was confirmed by Russia's defence ministry.
"The group of ships passed through the Tsugaru Strait for the first time as part of the patrol," the ministry said in the statement.
The area is regarded as international waters.
"The tasks of the patrols were the demonstration of the Russian and Chinese state flags, maintaining of peace and stability in the Asia-Pacific region, and guardianship of the subjects of maritime economic activities of the two countries," the ministry added.
In May, Russian President Vladimir Putin said that Moscow-Beijing relations had reached their "highest level in history" in a video conference with Chinese counterpart Xi Jinping.
Mr Putin and Mr Xi have developed increasingly close ties, based in part on their shared identities as autocratic leaders who repress all political opposition.
Reuters/ABC
