Japan and the United States launched their biggest-ever joint military exercises Friday, with the South Korean military taking part as an observer, according to Japan's defense ministry.

Following straight on the heels of similar drills held in the Yellow Sea between the U.S. and South Korea, the drills in Japan, which will run for eight days at bases across Japan and in the air and on waters around them and are being called the "Keen Sword" drills will involve more than 34,000 Japanese and 10,000 American troops.

"This is a biyearly joint drill. Naturally, we take into consideration changes in the security environment in surrounding areas, but we are not targeting a specific country," Japanese Defense Minister Toshimi Kitazawa told reporters when asked about the significance of the latest exercises.

In terms of hardware, about 400 planes and 60 warships will participate, including the nuclear powered aircraft carrier USS George Washington, which took part in the Korean peninsula exercises, as well as Japan's Maritime Self-Defense Force's next-generation Aegis-equipped battle ships.

The exercise drills will include responding to ballistic missile attacks on Pacific islands, according to a statement by the Joint Staff of the Japan Self-Defense Forces, as well as base security, close air support, live-fire training, maritime defense and search and rescue training activities.

The core of the drills, according to authorities, will focus on counter-measures to a potential ballistic missile attack and will utilize Standard Missile-3 interceptors on the both U.S. and Japanese Aegis destroyers deployed to the Sea of Japan off the Noto Peninsula in central Japan and Patriot Advanced Capability-3 ground-to-air missiles currently stationed at bases from Hokkaido to Okinawa.

While the SDF and U.S. plan to simulate a ballistic missile attack on Japan, the interception will not involve the launch of any missiles authorities said, with the emphasis being on detection, tracking and "simulated" interception.

In addition, F-15 fighter jets from Komatsu base, the USS George Washington and Japan's "flat-top" helicopter carrying destroyer will be involved in anti-submarine naval exercises.

Japan and the U.S. will be joined by South Korea as an observer during the drills, in a similar move which saw Japanese troops take part in a joint U.S.-South Korean military exercises in July as observers.

The latest exercise was planned more than a year ago, according to a Japanese Self-Defense spokesman and as Japan relies solely on the U.S. for its military security under its pacifist constitution -- with its military not allowed to attack enemy territories -- the drills are aimed at coordinating effective combined exercises between the two allies, test new technology and maintain a sense of "joint cohesiveness and readiness," according to authorities.

Chinese Foreign Ministry spokeswoman Jiang Yu had said the U.S.- Japan joint exercise and their alliance should not damage the interests of third parties including China, adding that the international community does not support actions that escalate tensions.

The United States and South Korea concluded a four-day joint naval drill in waters west of the divided peninsula after the exchange of artillery fire last week between South Korea and the Democratic people's Republic of Korea (DPRK).

Jiang also had said "military alliances and displays of force cannot solve the issue", stressing that the only way to resolve the Korean Peninsula issue is through dialogue and negotiation.

China had proposed an emergency six-party consultations on the Korean Peninsula situation in Beijing in early December following the rising tensions on the peninsula.