Japan and the United States have agreed to relocate the site for flight drills by U.S. carrier-borne aircraft from Iwojima Island in the Pacific to a permanent site in Japan in fiscal 2009 at the earliest, Tokyo sources said Monday.

Tokyo and Washington will include the transfer agreement in a set of accords on the realignment of U.S. forces in Japan, they said. The site is used for night landing practice.

While the United States has asked to relocate the site to somewhere near its base in Iwakuni, Yamaguchi Prefecture, because the aircraft are to be transferred there from the Atsugi Naval Air Facility in Kanagawa Prefecture, the final decision has not been made due to concerns local opposition may be strong, they said.

The flight drills are currently conducted, on a temporarily basis, mostly on Iwojima, which lies about 1,200 km due south of Tokyo. They involve aircraft from the carrier USS Kitty Hawk.

Tokyo has explained to the city of Iwakuni and surrounding municipalities that the night drills will continue to be conducted on Iwojima for the time being and will not be moved to Iwakuni.

The U.S. Navy had conducted the drills at the Atsugi base, which is jointly used by Maritime Self-Defense Force aircraft, but changed the site to the island after Japan and the United States agreed to the relocation in 1989 in the face of local opposition.

But Washington has since called on Tokyo to provide a permanent facility that is much closer to Japan's main islands for the drills.