The United States has asked Japan to designate an area for a permanent field-carrier landing practice facility within 100 nautical miles, or 180 km, of Iwakuni Air Base in Yamaguchi Prefecture, sources involved in talks between the two sides said Friday.

The U.S. carrier-borne aircraft at the U.S. Naval Air Facility Atsugi in Kanagawa Prefecture are conducting landing practice on Iwojima Island at the moment, some 1,200 km from Atsugi, because of complaints about noise from residents. Washington hopes to permanently relocate the facility to the Seto Inland Sea area near Iwakuni or northern Kyushu.

The two countries agreed in May to relocate U.S. carrier-borne aircraft to Iwakuni from Atsugi by 2014 to more equally share the burden of the flight drills among residents. They hope to select a permanent site for an FCLP facility by July 2009 or soon afterward.

The United States presented the request in October at a meeting of diplomatic and defense officials working on the realignment of U.S. forces in Japan, saying a permanent facility would make the drills safer and more efficient, the sources said.

The U.S. side did not specify where the facility should be, but Japan said it will propose several cites by March, the sources said.

Basing the facility within 100 nautical miles of Iwakuni would allow carrier aircraft to complete the drills without having to refuel in flight.