TOKYO -- Japan's prime minister said for the first time Tuesday that at least part of a key U.S. military base will remain on the southern island of Okinawa, a move that could reduce tension with Washington but dent his sinking popularity and raise the ire of island residents.
A dispute over the relocation of Futenma Marine Corps airfield has become the focal point of U.S.-Japan ties since Yukio Hatoyama took office last September promising to move the base off Okinawa -- contrary to a 2006 agreement with Washington that called for it to be moved to a less crowded, northern part of the island.
But on his first visit to Okinawa as prime minister, Hatoyama conceded it would be difficult if not impossible to move Futenma's facilities off the island, which hosts more than half the 47,000 American troops stationed in Japan under a security pact.
Hatoyama essentially acknowledged that his government has been unable to come up with any other viable alternatives to Nago, the proposed relocation site in the north, and is shifting back toward the 2006 plan.
"Realistically speaking, it is impossible," he said, wearing a traditional Okinawan short-sleeved shirt. "We have reached a conclusion that it is difficult to relocate all of Futenma's functions outside the country or the island because of a need to maintain deterrence under the Japan-U.S. alliance."
Hatoyama's backtracking will likely drag down his public approval ratings, which have fallen to about 20 percent amid a political funding scandal and perceived lack of leadership, and could even hurt his party's prospects in July upper house elections.
The prime minister, who had set an end-of-May deadline for a final decision on Futenma, asked for residents' understanding in keeping some of the base's functions on Okinawa, while possibly moving other functions outside the island -- a division that Washington would likely find unacceptable.
"We must ask the people of Okinawa to share the burden," he said, adding that he "felt sorry" about the message he brought.
Okinawan residents have long complained about base-related noise, pollution and crime. Late last month, about 90,000 people gathered to demand that Futenma be moved off the island entirely.
Tensions on Okinawa over the huge U.S. military presence go back decades, but a furor erupted over a 1995 rape of a 12-year-old girl in which three American servicemen were convicted. Adding to the discontent was a 2004 crash of a U.S. helicopter that burst into flames on a university campus, although it caused no injuries on the ground.
While Futenma's fate remains uncertain, Hatoyama's apparent move back toward the 2006 agreement could bring a measure of relief from Washington, which has insisted that Japan keep its side of the deal, forged with the previous conservative Tokyo government, and proceed with the move to Nago.
American officials say that keeping the base in Okinawa is important for maintaining regional stability given the island's geographical location -- near Taiwan and China and not far from the Korean peninsula.
The airfield, set in the middle of an urban area, is home to about 2,000 Marines and is one of the corps' largest facilities in the Pacific.
U.S. defense officials have also said that by delaying action on Futenma, Washington cannot move ahead on a broader 2006 military reorganization agreement that also involves sending 8,000 of the 18,000 Marines on Okinawa to the U.S. territory of Guam, largely to alleviate the burden on Okinawans.
Hatoyama acknowledged that he lacked awareness when he entered office about the logistical reasons for keeping the Futenma Marine facility on the island.
"As I learned more about the situation, I've come to realize that they are all linked up (with the other troops) as a package to maintain deterrence," he said.
According to Japanese media reports and vague comments from Cabinet members, Tokyo's latest plan roughly follows the existing agreement and will move Futenma to a location off the coast of Camp Schwab, a U.S. base near Nago.
Instead of building the base on reclaimed land, as outlined in the original plan -- which environmentalists say would damage marine life -- Tokyo is floating a plan to construct a runway on a jetty that sits on pilings that go into the sea floor. It also proposes moving part of Futenma's helicopter unit to Tokunoshima, an island 80 miles (130 kilometers) north of Okinawa. But residents there fiercely oppose such an idea.
Meanwhile, Japanese and U.S. officials launched working-level talks Tuesday in Tokyo on details of the Futenma relocation.
Analysts said Hatoyama's reversal will likely make him appear wishy-washy and depress his approval ratings. That could bode poorly for the ruling Democratic Party of Japan's prospects in July elections, although the opposition Liberal Democratic Party is in disarray.
"Hatoyama has already lost the trust and support of the general population," said Tsuneo Watanabe, a senior fellow at the Tokyo Foundation, a think tank. "Hatoyama may be replaced before the upper house elections."
"The U.S. side will welcome the (Tokyo) government realizing the original plan as necessary," he said. "But for the people who expected new things from Hatoyama, this is a big disappointment."