Tokyo and Washington plan to stipulate that the site of a contentious U.S. Marine Corps base in Okinawa be returned to Japan's control within nine years and that the handover of five other facilities and areas leased to the U.S. military in the prefecture be hastened, government sources said.

The two sides want to craft a plan, possibly in the first half of April, to return facilities and land south of U.S. Kadena Air Base in an effort to reduce the concentration of U.S. facilities and troops in Okinawa.

The five sites are Camp Zukeran, the Makiminato Service Area, Camp Kuwae, part of the port of Naha and Kuwae Tank Farm No. 1.