The 10th joint sea search-and-rescue exercises near the Japanese naval base at Sasebo were scheduled to begin on September 9.
The source, speaking on condition of anonymity, told RIA Novosti that Japan had followed a decision by NATO countries, which earlier decided to suspend all joint military maneuvers with Russia. However, he said Russia should not jump to conclusions over Japan's decision.
"The Japanese government highly appreciates the fact that Russia does not equate the development of air and missile defenses around Japan to the placement of a U.S. missile shield in Europe," the source said.
Meanwhile, the spokesman for Russia's Pacific Fleet, Capt. 1st Rank Roman Martov, told RIA Novosti on Tuesday that Russia had not received any official statement from Japan regarding the postponement of the exercise.
"The large ASW ship Admiral Panteleyev is ready to sail to the Sea of Japan on September 5-6 to participate in the joint exercise," he said.
Japan and Russia have been conducting annual joint search-and-rescue exercises in the Sea of Japan since 1998.
