The commander of U.S. forces in Japan said he's confident that around half of the training using MV-22 Osprey transport aircraft can be conducted outside Okinawa Prefecture.

"I don't have the data, but I suspect that we are not having a problem reaching that goal," Lt. Gen. Salvatore Angelella said during a telephone conference call Monday from Tokyo.

Prime Minister Shinzo Abe has pledged to reduce the burden on Okinawa from hosting most U.S. military bases in Japan. He made that pledge, and to provide ¥300 billion in development funds yearly through fiscal 2021, to get Okinawa Gov. Hirokazu Nakaima to give the go-ahead to contentious land reclamation work.

In late December, Nakaima approved the landfill work needed to relocate the operations currently conducted at U.S. Marine Corps Air Station Futenma, in Ginowan, to a new base to be built in an offshore area in Nago, a major breakthrough in the contentious plan.