Photo/IllutrationOkinawa Governor Takeshi Onaga at a news conference in Naha on July 27 (Asahi Shimbun file photo)

Okinawa Governor Takeshi Onaga, who led an anti-U.S. military base movement on the southern Japanese island, died of pancreatic cancer on the night of Aug. 8 at age 67, Japanese media said.

He was operated on for the cancer in April and resumed work in May.

Onaga, who had lost considerable weight, said he was determined to fulfill his duties and live up to the expectations of Okinawans who supported his fight against a U.S. military base relocation plan and the heavy American troop presence on the small island.

Deputy Governor Kiichiro Jahana said earlier Wednesday that Onaga had lost consciousness on Tuesday. Jahana said he was temporarily assuming Onaga's duties. There will be an election within 50 days under Japanese local election rules.

Onaga was elected governor in November 2014 on a pledge to scrap plans to relocate a contentious U.S. Marine Corp. air station to a less dense part of the island and close it instead. Opponents of the relocation plan say it only shifts the burden of hosting the facility elsewhere, and the base should be moved off the island entirely.

A native of Naha, the prefectural capital, Onaga often confronted top officials of the central government, saying Tokyo's approach was high-handed and neglected the will of Okinawans. In 2015, four months after taking office, Onaga criticized Japanese Chief Cabinet Secretary Yoshihide Suga for "looking down on" Okinawans, citing Suga's comment that the government planned to steadfastly go ahead with the relocation plan.

About half of the 50,000 American troops in Japan are stationed on Okinawa.

Onaga filed a series of lawsuits against the central government, seeking a court injunction to stop landfill at the planned relocation site. He was preparing another legal action when he died.

Onaga has said the Futenma issue dates back to the U.S. confiscation of Okinawan land after Japan's World War II defeat. He said Tokyo's postwar defense stance under the Japan-U.S. security alliance is built on Okinawa's sacrifice.

The dispute over the relocation of the Futenma base reflects centuries-old tensions between Okinawa and the Japanese mainland, which annexed the islands, formerly the independent kingdom of the Ryukus, in 1878. In the final days of World War II, Okinawa became Japan's only home battleground, and the island remained under U.S. rule for 20 years longer than the rest of Japan.

Onaga was born in 1950 when Okinawa was still under U.S. occupation.