Tokyo may propose to Washington discussions on an earlier than scheduled relocation of U.S. Marine Corps Air Station Futenma in Okinawa Prefecture, government sources said Saturday.

The government is contemplating the move as part of efforts to win approval by Okinawa Gov. Hirokazu Nakaima for landfill work necessary to move ahead with a bilateral agreement to relocate the base within the prefecture, according to the sources.

Nakaima, who plans to make a decision by Dec. 31 on whether to authorize the request, has asked the central government to ensure the closure of the Futenma base within five years, among other conditions.