Okinawa Gov. Denny Tamaki on Saturday announced his bid for a second four-year term, likely facing a challenger backed by the Liberal Democratic Party in the Sept. 11 election.

Tamaki made clear at a news conference his continued opposition to the controversial relocation of a U.S. Marine Corps base within the prefecture, saying construction of a new airfield off the eastern coast is "absolutely unacceptable."

Political forces in Okinawa that oppose Air Station Futenma's relocation to the Henoko coastal area in Nago are expected to be fully behind the 62-year-old's re-election bid.

The LDP has already decided to back former Ginowan Mayor Atsushi Sakima, who was defeated by Tamaki in the 2018 election, making the next election likely to be another faceoff between the two.

The central government and the Okinawa government have been locked in a standoff over the relocation project following the governor's disapproval in November of a design change made necessary by the discovery of soft ground in the Henoko waters planned for reclamation.

At the news conference, Tamaki blasted the project, saying that even the central government cannot say when the construction will be completed.

The existing project "won't lead to elimination of Futenma's risks that must be done as soon as possible," the governor added.

The air base is located in a densely populated area and locals have long decried its presence, due in no small measure to the risks of accidents posed by it.

Tamaki also cited recovery of the local economy from the coronavirus pandemic as one of the key issues facing the prefecture, which depends heavily on tourism.

The governor had previously served as a House of Representatives member and belonged to the now-defunct Democratic Party of Japan.