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 “show the flags of the states of Russia and China, to maintain peace and stability in the Asia-Pacific region and also to protect the facilities of maritime economic activity of the two country, ”the statement said.
“During the patrol, the group of warships crossed the Tsugaru Strait for the first time,” the statement added.
Tsugaru Strait is a 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.
The two countries have an ongoing military partnership and have conducted a series of joint military exercises, the most high-profile of which was “Vostok 2018,” which involved a mock battle in which a Russian-Chinese coalition fought a fictitious enemy.
In August, Russia and China again joined forces to use a joint command and control system, with Russian troops integrated into Chinese formations, according to a statement from the then Chinese Defense Ministry.
Russian leader Vladimir Putin has an ally in Chinese President Xi Jinping, with Chinese Foreign Ministry spokesman Zhao Lijian saying at a press briefing in June that the two countries were “united as a mountain” with a “unbreakable” friendship.
CNN’s Brad Lendon, Nectar Gan, Ben Westcott, Mary Ilyushina and Nathan Hodge contributed to this report.