The governor of Okinawa expressed bafflement at a decision by U.S. Forces Japan to challenge descriptions of the southernmost prefecture as hosting nearly three-fourths of American military installations in the nation as a “misrepresentation of the facts.”

USFJ, headquartered in Tokyo, posted the following on its Facebook page June 23: “There is a common misperception about U.S. military bases in Japan. It is often said that 75 percent or more of all American military facilities in Japan are located on Okinawa. This is a misrepresentation of the facts.”

Governor Takeshi Onaga blasted the post on June 28, calling it an attempt to “manipulate” the facts.

“I was stunned,” he told reporters. “Tokyo and Washington have both discussed the U.S. base issue in Okinawa in terms of area of the land and there has been no dispute over it until now. The recent post appears to be an attempt to manipulate the facts.”

The post went on to say, “In fact, 39 percent of U.S. exclusive use facilities and 49 percent of total SOFA members reside in Okinawa,” referring to American service members and civilian U.S. base workers under the Japan-U.S. Status of Forces Agreement.

The 39 percent, it said, represents the number of U.S. bases in Okinawa, at 33, out of 85 across Japan.

The 39 percent runs counter to the oft-mentioned 74 percent, which represents land area held by U.S. bases in Okinawa against the total devoted to American military facilities in Japan. The 74 percent is the standard figure cited by the Defense Ministry and most domestic and international news organizations.

Many Okinawans were baffled by the timing of the post, which coincided with an annual memorial service for all the victims of the 1945 Battle of Okinawa during World War II.

Contacted by The Asahi Shimbun for comment, Maj. John Severns, USFJ's deputy director of public affairs, said, “There was no specific reason this one was issued” other than that it was in line with U.S. base policy to issue a "USFJ Fact of the Week" on a weekly basis.

He added that USFJ presented the ratio of U.S. bases in Okinawa against the overall number in Japan because “Much of the confusion over this (U.S. bases) issue occurs when people confuse facilities for areas.”

He said USFJ cited the 39 percent figure to “help provide additional context for any discussion of U.S. force posture in Japan.”

The Japanese version of the text was posted on June 24.

Defense Minister Gen Nakatani declined to comment on the post.

“The Defense Ministry states that the ratio of U.S. bases in Okinawa Prefecture is 74 percent, compared with the whole area of land occupied by U.S. bases in Japan,” he said after a Cabinet meeting on June 28. “But there are various ways to present data to the public that show things in a different light. I will refrain from making further comment.”

U.S. military facilities in Okinawa range significantly in size and acreage. For example, the Kumejima Range is a 2,000-square-meter training ground on Kumejima island to the west of Okinawa’s main island, whereas Camp Gonsalves, a U.S. Marine Corps jungle warfare training area in the northern part of the main island, is larger than all of the U.S. bases outside the prefecture combined.

“There is no point in simply presenting the issue of U.S. military installations in terms of numbers (and not acreage),” said Manabu Sato, a professor of international politics at Okinawa International University. "U.S. forces apparently want to downplay Okinawa's burden so that it does not look as great as reported."

Anti-U.S. base sentiment among Okinawans is very strong as the central government tries to push forward with plans to relocate the Futenma base in Ginowan to the Henoko district of Nago.

Onaga, the governor, is demanding the closure of the Futenma airfield and objects to relocating it within the prefecture, citing the disproportionate burden Okinawa has been shouldering to host U.S. military bases in Japan. Okinawa accounts for 0.6 percent of Japan's land mass.

(Yusuke Fukui contributed to this article.)