China has voiced stern opposition to Japan's joint military exercise operations with "extraterritorial nations."

"We sternly oppose Japan wooing extraterritorial nations for joint military drills that only increase regional tensions," Ministry of Defense spokesman Yang Yujun said at a Thursday press conference.

Yang made the remarks in reply to a question regarding a potential Japan-U.S. joint military exercise in Okinawa.

Japan's Kyodo News reported that Japan and the United States were considering a joint military drill for early November.

"We will keep a close eye on developments concerning the issue," Yang said.

Yang said Japan is to blame for the degradation of military-to-military exchanges between China and Japan.

Media reports said China and Japan have shelved a plan to build a maritime liaison mechanism between their defense departments. Both countries agreed in June to partially initiate the mechanism later this year.

The current tensions between China and Japan are a result of the Japanese government's illegal "purchase" of part of the Diaoyu Islands, Yang said, adding that Japan is fully responsible for the situation.

"We hope the Japanese side will correct its mistakes and make efforts for the sake of China-Japan relations," said the spokesman.

Yang said increasing Japanese surveillance activities directed at China have impaired China's sovereignty and security and become a source of problems between the two countries.

"We demand the Japanese side to stop infringing upon China's sovereign interests and take effective measures to prevent unpredictable incidents from happening," he said.

Japan should reflect on its strained ties with its neighbors instead of blindly displaying its power, Yang said.

(Xinhua News Agency October 25, 2012)