TOKYO, April 11. /TASS/. Japan has serious concerns about the joint activity of Russian and Chinese armed forces near its borders, according to an annual report of the Japanese Foreign Ministry published on Tuesday.

"The joint actions of Chinese and Russian armed forces near the Japanese border raise serious concerns in terms of Japan’s security," the Diplomatic Bluebook reads. According to the Japanese Foreign Ministry, Russia and China have boosted military cooperation in recent years as they hold joint exercises and patrols close to Japan, using bombers and warships.

Previously, the Russian Defense Ministry has repeatedly stressed that such drills and patrols are conducted in strict compliance with international law and do not violate foreign airspaces.