The joint Chinese-Russian naval exercise, in which a fleet of 10 warships circled the main Japanese island, was presented by the two countries as a means of ensuring stability in the volatile region.

Analysts, on the other hand, believe that The exercises are likely to have the opposite effect, potentially re-igniting regional tensions and giving prominence to the Japanese government's claims that it needs to increase military spending to counter Chinese aggression.

The naval maneuver of the two navies was announced as the first joint Sino-Russian naval patrol in the western Pacific. The ships crossed the Kugaru Sea, which divides the mainland island of Japan and its northern island of Hokkaido, before heading off the east coast of Japan and then back to the Chinese coast.

Although foreign ships were allowed to sail through the Osumi and Kugaru Straits, which are considered international waters, the maneuvers were closely monitored in Japan and its navy.

"This will reinforce Japan's claims that China poses a potential threat, so they must increase their own defense spending and readiness to deal with it," the Pentagon said in a statement.

The Japanese Ministry of Defense described the exercises, which lasted last week, as "unusual".

The Sino-Russian fleet consisted of five warships from each country, with destroyer-class ships as well as frigate-class Corvettes and auxiliary warships.

The Chinese military announced that The two navies are deployed in the East China Sea, where they are conducting "Joint Exercise and Joint Cruise to Advance Sino-Russian Strategic Partnership for the New Era and Effectively Improve Joint Operations Opportunities, Leading to Maintaining Joint International and Regional Strategic Stability." said Beijing.

Russia's Defense Ministry says the purpose of the joint patrol is "to demonstrate the state flags of Russia and China, to maintain peace and stability in the Asia-Pacific region, as well as to protect the capacities for maritime economic activity of both countries ".