The Okinawa Prefectural Government has approved the start of rock drilling off Henoko, part of land reclamation work on a replacement facility for a key U.S. military base in the prefecture.

The Defense Ministry can now legally dig out rocks and other sediment from the seabed and build protective banks and other facilities, so the operations of U.S. Marine Corps Air Station Futenma in Ginowan can eventually be relocated.

"It is an important step" toward moving the base from its current location in the crowded city of Ginowan, Defense Minister Itsunori Onodera told reporters on Thursday in Tokyo.