The United States and Japan have reached a deal to break a long stalemate on a military base in Okinawa, taking up a key impediment in ties days ahead of a summit, a senior US official said Thursday.
Kurt Campbell, the assistant secretary of state for East Asian and Pacific Affairs, said that the two nations would jointly release a deal at 0200 GMT Friday and voiced hope that it would enjoy support in both countries.
Campbell said that the deal would maintain a plan to move a base to a controversial new location on the crowded island of Okinawa but also include "immediate" steps to shift the US military to the US territory of Guam.
"We think it breaks a very long stalemate that has plagued our politics, that has clogged both of our systems, that has made it difficult to deal with the critical and crucial issues that confront the United States and Japan," Campbell said.
Speaking at the Center for Strategic and International Studies, a Washington think-tank, Campbell held off on announcing the details of the deal but said it would be "very clear" on troop levels and show financial commitments by Japan.
The agreement would be part of a larger US strategy in Asia. The United States is stepping up military ties with Australia, the Philippines and Singapore amid concerns in the region over China's rapid rise.
The deal comes just ahead of a visit to Washington by Prime Minister Yoshihiko Noda, who will meet with President Barack Obama on Monday for what both sides hope will be a demonstration that the alliance is back on track.
Japan and the United States have long clashed over Okinawa, the site of sporadic tensions with US troops. Around half of the 47,000 US troops in Japan are based on the strategically-located island near Taiwan.
In 2006, the United States agreed to shift the Futenma air base -- a longtime source of grievance as it lies in a crowded urban area -- to a quiet stretch of seashore, with some 8,000 Marines leaving Okinawa for Guam.
But some activists in Okinawa pressed for the base to be removed completely. The controversy felled one Japanese prime minister, Yukio Hatoyama, who failed to fulfill campaign pledges in 2009 to renegotiate the deal.
Campbell said that the plan to shift to the new facility would remain and acknowledged that there were still more details to sort out in the long-running controversy.
"But at a fundamental level, we think this agreement moves the ball very substantially down the field in a way that no one would have anticipated a few months ago," Campbell said.
Three leading US senators -- Carl Levin, John McCain and Jim Webb -- have raised objections over the pending base deal, triggering a delay in the announcement.
In a letter on Tuesday, the senators voiced concern that the agreement did not clearly address concerns with the base plan, including costs.
"It is our position that any announcement on this critical matter that goes beyond an agreement in principle at this time would be premature and could have the unintended consequences of creating more difficulties for our important alliance," they wrote in a letter to Defense Secretary Leon Panetta.
Campbell voiced confidence that the senators' concerns had been addressed.