Three influential U.S. senators called Thursday for a fundamental re-examination of the 2006 agreement between Tokyo and Washington to relocate 8,000 U.S. Marines from Okinawa to Guam after a replacement facility for U.S. Marine Corps Air Station Futenma is built in Okinawa.

"Much has changed since the U.S.-Japan Roadmap for Realignment Implementation agreement was signed in 2006. The projected times [for completion by 2014] are totally unrealistic. Political realities in Okinawa and Guam, as well as the enormous financial burden imposed on Japan by the devastation resulting from the disastrous earthquake and tsunami must also be considered," said Sen. Carl Levin, a Democrat from Michigan and chairman of the Armed Services Committee, in a joint statement with Republican Sen. John McCain and Democratic Sen. Jim Webb.

McCain serves on Levin's committee as the ranking minority member, while Webb is chairman of the Senate Committee on East Asian and Pacific Affairs and once served in Okinawa as a U.S. Marine.