Okinawa Prefecture on Wednesday rejected the central government's order to endorse its modified plan on landfill work for the transfer of a key U.S. base, in a move likely to prompt the administration of Prime Minister Fumio Kishida to take legal action.

The central government issued the order late last month as part of its attempt to move ahead with a procedure allowing the land minister, instead of the Okinawa governor, to approve modifications to the project, in order to reinforce soft ground at a designated construction site.

If the central government wins in what will likely be an upcoming case at the Fukuoka High Court's Naha branch, and Okinawa Gov. Denny Tamaki still does not approve the plan, land minister Tetsuo Saito will endorse it so that the landfill work in the southern island prefecture can progress.

The central government and Okinawa Prefecture have long been at odds over relocating U.S. Marine Corps Air Station Futenma in the residential district of Ginowan to the less densely populated Henoko coastal area in Nago within Okinawa.

In 1996, an agreement was reached with the United States on a relocation plan for the base, with Japan selecting Henoko as the new site in 1999.

But residents of Okinawa continue to strongly oppose relocating the base within the prefecture, which already hosts the majority of the U.S. military's facilities in Japan.

In early September, the Supreme Court turned down an appeal by Okinawa Prefecture against the central government's earlier order for Okinawa to rescind its disapproval of the modified landfill work.

The deadline for the latest order from the land minister is Wednesday.