The government began constructing a new sea wall Monday in Okinawa as part of a controversial plan to relocate a U.S. military base within the prefecture, the local defense bureau has said.

The move is expected to draw fresh backlash from the Okinawa Prefectural Government, which has persistently opposed the Japan-U.S. plan to move U.S. Marine Corps Air Station Futenma from the crowded residential area of Ginowan to the less populated coastal zone of Henoko in Nago.

Under the plan, some 157 hectares of land will be reclaimed to construct a V-shaped runway.