The Chinese and Russian navies today began a nine-day joint drill. It is the second such drill this year.
The Joint Sea-2015 II exercise is being held in the Peter the Great Gulf, waters off the Clerk Cape and the Sea of Japan.
A total of 23 vessels and two submarines are participating. Chinese navy supply ship the Taihu Lake conducted its mission to supply three warships.
China's defense ministry said in July that a key purpose of the drills is to "further enhance their capabilities of jointly coping with maritime security threats."
China and Russia have held five joint naval exercises since 2005.