Japan and the U.S. postponed a Wednesday joint statement on the return of five U.S. bases and facilities in Okinawa after three influential U.S. Senators expressed concern over a lack of cost estimates and how the agreement fits into the broader U.S. strategy for the region.

The joint statement was to have been issued Wednesday, four days before Prime Minister Yoshihiko Noda was due to visit Washington for a summit with U.S. President Barack Obama.

It was to call on the U.S. to immediately return a number of districts in Okinawa where bases, including Camp Zukeran (Camp Foster), are located.