Japan's cost for U.S. Marines' move to Guam may rise to $3.5 bil.

The U.S. Andersen Air Force Base is pictured in Guam in this Sept. 12, 2004 file photo. (Mainichi)

 Japan and the United States began making adjustments on Thursday to increase to $3.5 billion from $2.8 billion the costs the Japanese government will shoulder to transfer U.S. Marine personnel from Okinawa Prefecture to the U.S. territory of Guam, sources close to Japanese-U.S. relations said.

The two governments agreed in 2009 on Japan's contribution of $2.8 billion to cover the cost of constructing buildings for a command center and other facilities, including schools, on the Pacific island.

But in bilateral talks that began in February, the United States has asked Japan to increase its cost-sharing under growing pressure from the U.S. Congress to cut expenditures. Japan, which resisted the move initially, has since relented to preserve the bilateral alliance, according to the sources.

As a result of the ongoing review, the number of Marines to be moved from Okinawa to Guam is expected to be reduced to 4,200 from 4,700, while the number of Marines to remain on Okinawa is expected to reach 11,300, above the 10,000 threshold confirmed by the two countries in February.

The two countries had agreed in 2006 to move 8,000 of the 18,000 Marines on Okinawa. Given the projected reduction in the number of personnel to be moved -- roughly by half -- questions could arise in Japan about increasing the country's share of costs.

Aside from the 4,200 Marines expected to be moved to Guam from Okinawa, 500 Marine helicopter personnel will be moved there from the Marines' air base in Iwakuni, Yamaguchi Prefecture, as agreed by the two countries in 2006.

Japan and the United States need to move 4,800 Marines from Okinawa if they are to keep the 10,000 threshold for the number of Marine personnel stationed on Okinawa as confirmed by the two countries on Feb. 8.

Of the 4,800, 3,500 will be moved to Australia, Hawaii and the mainland United States. The U.S. side sought to move the remaining 1,300 to the Iwakuni Air Station but gave up the effort due to local opposition.

While the Japanese side asked for the personnel to be moved outside of the country, the U.S. side did not yield to the request, arguing that the personnel would remain on Okinawa if they cannot be moved to Iwakuni.

In the end, the Japanese side gave in, making it likely that the number of Marines to stay on Okinawa will reach 11,300, according to the sources.

While the two governments are working to reduce the number of Marines to remain on Okinawa, the personnel are expected to exceed the threshold by the hundreds, the sources said.

Get our updates FREE