Okinawa Gov. Hirokazu Nakaima granted permission Friday to start offshore fill work for building the base to replace U.S. Marine Corps Air Station Futenma, ending his long opposition to allowing a successor facility to be built in the prefecture.

The decision comes after years of political maneuvering and persistent public opposition. It marks a major breakthrough in the stalled effort to close Futenma in the crowded Okinawa city of Ginowan and replace it with a new airstrip next to Camp Schwab on the less-populated Henoko coast in the city of Nago, in line with a 1996 Japan-U.S. accord.

"We decided to approve the application for the fill work, as we judged it contains all possible steps that could be taken at present to protect the environment," Nakaima said at a news conference in Naha.