A group of naval vessels from Russia and China conduct a joint maritime military patrol in the waters of the Pacific Ocean, in this still image taken from video released on October 23, 2021.
CNN  — 

Russian and Chinese warships have conducted the first ever joint patrol in the western part of the Pacific Ocean, the Russian defense ministry said in a statement on Saturday.

The patrols involved a total of 10 warships, five from each nation, and lasted a week, from Sunday, October 17 to Saturday, October 23, covering 1,700 nautical miles, according to the Ministry.

The objective of the joint patrol was to “demonstrate the state flags of Russia and China, maintain peace and stability in the Asia-Pacific region and also protect facilities of both countries’ maritime economic activity,” the statement read.

“During the patrol, the group of warships passed through the Tsugaru Strait for the first time,” the statement added.

The Tsugaru strait is body of water between the Japanese islands of Honshu and Hokkaido in the northern part of the country, connecting the Sea of Japan with the Pacific Ocean. 

In addition to the patrol, the two navies practiced joint tactical maneuvers and did a series of military drills, the statement added.

The two countries have an ongoing military partnership and have conducted a series of joint military drills, the most high profile of which was “Vostok 2018,” which involved a simulated battle in which a Russian-Chinese coalition fought a fictional enemy.

In August, Russia and China joined forces once again to use a joint command and control system, with Russian troops integrated into Chinese formations, according to a statement by China’s defense ministry at the time.

Russia’s leader Vladimir Putin has an ally in Chinese President Xi Jinping, with Chinese foreign ministry spokesperson Zhao Lijian telling a news briefing in June that the two countries were “united like a mountain” with an “unbreakable” friendship.

CNN’s Brad Lendon, Nectar Gan, Ben Westcott, Mary Ilyushina and Nathan Hodge contributed to this report.