MOSCOW, Russia: Russia and China have conducted their first-ever joint patrol in the western part of the Pacific Ocean, the Russian defense ministry announced.

Ten warships, five from each nation, participated in the week-long patrol from Sunday, October 17 to Saturday, October 23.

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.

Among other locations, the patrol was held in the Tsugaru strait between the Japanese islands of Honshu and Hokkaido in the northern part of the country.

China and Russia maintain a military partnership and have conducted a series of joint military drills, including a simulated battle in which a Russian-Chinese coalition fought a fictional enemy.

In June, Chinese foreign ministry spokesperson Zhao Lijian told a news briefing that the two countries were “united like a mountain” with an “unbreakable” friendship.