Photo/IllutrationAir Self-Defense Force members participate in a training exercise in June involving the Patriot Advanced Capability 3 (PAC-3) surface-to-air guided missile unit at Camp Asaka in Tokyo's Nerima Ward. (Takayuki Kakuno)

The Air Self-Defense Force will test its capabilities to shoot down North Korean ballistic missiles in a joint training exercise with U.S. troops at the hub of the two allies' defense cooperation--Yokota Air Base.

The exercise, which could be held as early as August, would continue a series of moves designed to placate a Japanese population worried about increasing military provocations by North Korea in the form of ballistic missile launches.

A Patriot Advanced Capability 3 (PAC-3) surface-to-air guided missile unit of the ASDF will be deployed to the base, according to government sources.

The unit includes a launch vehicle, radar system and guidance device.

U.S. Air Force service members would participate in the exercise to confirm the procedures to be followed in the event of a launch.

The SDF's ballistic missile defense exercises have been open to the media around Japan since June, and the joint exercise at Yokota is considered part of that.

Still, Yokota Air Base, in western Tokyo, not only serves as command center for U.S. Forces Japan, but also is home to the ASDF's Air Defense Command. In that sense, Yokota is the key base as a command center for the SDF's ballistic missile defense system as well as for defense of Japanese airspace.

A Defense Ministry source described Yokota as "the symbolic base for the ongoing move toward closer cooperation in the Japan-U.S. security alliance."

Because of its key role, Yokota could be a target for North Korea if it launched ballistic missiles toward Japan.

Consideration at one time had been given toward a joint training exercise at Misawa Air Base in northern Aomori Prefecture because that base is jointly utilized by the ASDF and U.S. Air Force, according to government sources.

However, officials in the prime minister's office insisted that Yokota be used for the training exercise on the grounds the site would provide not only a stronger show of bilateral cooperation, but would also be significant in demonstrating the air defense capabilities of the Japanese capital.

Yokota Air Base has been included as one candidate site for deploying the PAC-3 missile unit under a defense plan compiled against possible ballistic missile attacks.

The joint training exercise will serve as preparation for such a scenario and allow the government to demonstrate it is responding to provocations from North Korea.