WASHINGTON (AP) ― About 9,000 U.S. Marines stationed on the Japanese island of Okinawa will be moved to the U.S. territory of Guam and other locations in the Asia-Pacific, including Hawaii, under a U.S.-Japan agreement announced Thursday.

The move is part of a broader arrangement designed to tamp down tensions in the U.S.-Japan defense alliance stemming in part from opposition in Okinawa to what many view as a burdensome U.S. military presence.

It also reflects a desire by the Obama administration to spread U.S. forces more widely in the Asia-Pacific region as part of a rebalancing of U.S. defense priorities in the aftermath of a decade of war in the greater Middle East.

The agreement was outlined in a joint statement issued Thursday night by Secretary of State Hillary Rodham Clinton and Defense Secretary Leon Panetta and their Japanese counterparts.

Citing an “increasingly uncertain security environment” in the Asia-Pacific region, they said their agreement was intended to maintain a robust U.S. military presence to ensure the defense of Japan.

“Japan is not just a close ally, but also a close friend,” Panetta said in a separate comment. “And I look forward to deepening that friendship and strengthening our partnership as, together, we address security challenges in the region.”

The joint statement made no mention of a timetable for moving the approximately 9,000 Marines off of Okinawa. It said it would happen “when appropriate facilities are available to receive them” on Guam and elsewhere.

Under the new agreement, about 10,000 Marines will remain on Okinawa, which has been a key element of the U.S. military presence in Asia for decades. The U.S. also has a substantial Air Force presence on Okinawa.

“I think we have made some progress and this plan offers specific and forward-looking action,” said Japan’s Foreign Minister Koichiro Gemba, who added that Japan wanted to “reduce the burden on Okinawa.”

Japan, including Okinawa, is a linchpin of U.S. strategy for deterring aggression in the region and for reinforcing the Korean peninsula in the event North Korea attacked South Korea.

The Obama administration believes the new agreement with Japan will make the alliance more sustainable, while also giving the Marines more regional flexibility.

Between 4,700 and 5,000 Marines will relocate from Okinawa to Guam, according to a U.S. defense official who briefed reporters on some of the details before the agreement was official announced in Tokyo and Washington.

The remainder of the 9,000 who are to relocate from Okinawa will move to Hawaii or be part of a rotational presence in Australia and elsewhere in the region, the official said. The official spoke on condition of anonymity because he was previewing the official announcement.

The official would not say how many would be moved to Hawaii. Earlier this week, Hawaii Gov. Neil Abercrombie said he expects around 2,700 Marines will be shifted there.

Of the $8.6 billion estimated cost of relocating Marines to Guam, Japan agreed to pay $3.1 billion, the official said. The total cost includes an unspecified amount for possible construction of new training ranges in the Northern Mariana Islands that could be used jointly by U.S. and Japanese forces, he said.

The agreement also calls for a phased return to Japanese control of certain parcels of land on Okinawa now used by the American military.

The shift of Marines from Okinawa to Guam has been in limbo for years because it was linked to the closure and replacement of Marine Corps Air Station Futenma. Okinawans fiercely oppose Futenma and believe the base should simply be closed and moved overseas or elsewhere in Japan. The U.S., however, has insisted that Japan find a Futenma replacement on Okinawa.

That issue remains unresolved.

Although many Okinawans welcome the reduction of troops, they believe their main island still has too many bases on it, and say the military presence causes congestion, leads to military-related crime and increases the possibility of civilians who live near the facilities being injured in accidents such as helicopter or aircraft crashes.

The whole dispute over the U.S. military presence on Okinawa has its roots in the 1995 kidnapping and rape of a schoolgirl by three American servicemen. Top U.S. government officials publicly apologized for the crime, but tensions continued to grow despite a strong desire by Tokyo and Washington to maintain their historically close military and political alliance.

The accord was timed for completion and public announcement before Japanese Prime Minster Yoshihiko Noda’s scheduled visit to Washington on Monday for talks with President Barack Obama.