Updated

The planned reorganization of American forces in east Asia, including on the southern Japanese island of Okinawa, is unworkable and unaffordable, three influential U.S. senators said Wednesday.

The Defense Department should re-examine its plans for South Korea, Guam and Okinawa — where many islanders oppose the presence of U.S. forces. A 2006 agreement with Japan aimed at decreasing America's military footprint is outdated and imposes an "enormous financial burden" on the U.S. ally as it recovers from a huge earthquake, the senators said.

Carl Levin and John McCain, the two highest-ranking members of the Senate Committee on Armed Services, and Jim Webb, chairman of the Senate Foreign Relations subcommittee for east Asia and the Pacific, made the recommendations in a joint statement. They offered alternatives they say would save billions but still keep U.S. military forces in the region.

Levin, of Michigan, and Webb, of Virginia, are Democrats, and Arizona's McCain is Republican.

Spokeswoman Cmdr. Leslie Hull-Ryde said Wednesday that the Defense Department remained committed to its plans for Japan, reiterated in a May 2010 joint statement.

"These agreements are good for the people of Okinawa, Japan as a whole, and the U.S.-Japan alliance," she said. "After the relocation is completed, the average citizen of Okinawa will see and hear far fewer U.S. troops and aircraft than they do today."

Officials at Japan's Foreign Ministry said Thursday that they were aware of the U.S. senators' statement, but stressed that Tokyo has no plans to alter its position regarding the relocation plan.

Okinawans have long complained about pollution, noise, crime and other problems associated with U.S. military bases across the island, which hosts more than half the 47,000 U.S. troops in Japan. The previous prime minister, Yukio Hatoyama, was forced to resign last year after promising and failing to get Marines off the island altogether.

Under the 2006 agreement, Marine Corps Air Station Futenma, located in a heavily populated southern part of Okinawa, would be closed and its air operations relocated to a less crowded northern area at Camp Schwab, where a new airfield would be built. Some 8,000 Marines would also be shifted to the U.S. territory of Guam by 2014. Japan would foot much of the multibillion-dollar relocation bill.

Webb said both the U.S. and Japanese governments seem determined to build the partially offshore facility at Camp Schwab but it could take as long as 10 years and is "rife with difficulties."

"The significant estimated cost growth associated with some projects is simply unaffordable in today's increasingly constrained fiscal environment," Levin said. "Political realities in Okinawa and Guam, as well as the enormous financial burden imposed on Japan by the devastation resulting from the disastrous March 2011 earthquake and tsunami, also must be considered."

Japanese media reports have suggested that officials in Tokyo are working behind the scenes to scrap the 2014 timeframe for moving the 8,000 troops from Okinawa to Guam. Tokyo is also having trouble convincing local leaders that a new facility on Okinawa should be built to replace Futenma.

Webb proposed moving the Marine Corps assets at Futenma in southern Okinawa to Kadena, an Air Force base further north in Okinawa where there is also opposition to the U.S. presence. Some Air Force assets could be shifted from Kadena to other areas in Japan and on Guam, particularly Anderson Air Force Base, a major B-52 bomber base that he said now operates at less than half of its capacity.

However, he noted, community leaders on Guam are also concerned of the environmental and social impact of a large increase in U.S. military presence. He proposed basing some Marines on Guam, then using rotating combat units that are home-based elsewhere.

The senators also took aim at the military's plans for South Korea, where the U.S. has more than 28,000 forces — a legacy of the 1950-53 Korean War that ended in an armistice rather than a formal peace treaty. They say plans to realign U.S. forces there should be put on hold pending further review.

Webb said some missions could perhaps be performed by South Korea's military instead of America's. He questioned plans to boost numbers of family members staying with the troops. The plans would drive up costs and there was "real potential that a destabilizing security situation in North Korea could unfold rapidly and unpredictably," he said.