QINGDAO, Shandong: Japan is "a little concerned" with the rising strength of the Chinese navy, Vice-Admiral Koji Kato, deputy chief of staff of the Japan Maritime Self-Defense Force, said yesterday.

"China has developed more and more ships and aircraft, in both quality and quantity," he told China Daily, after reviewing the Chinese submarine Great Wall-218.

"We should enhance mutual trust through more communications to avoid potential conflicts," he said through an interpreter.