Japan and the United States agreed last month that major repairs are necessary at U.S. Marine Corps Air Station Futenma in Okinawa Prefecture to keep the base usable for years to come, according to several sources.

With the plan to move the base farther north in the prefecture stalled by local opposition, the odds are high that the U.S. Marines will have to stay at the base in the crowded city of Ginowan for the indefinite future, the sources said Saturday.

The agreement to carry out extensive repairs was reached during bilateral vice ministerial-level talks held with foreign and defense officials in late February in Tokyo, the sources said.

At the meeting, Japanese and U.S. officials apparently determined that it is necessary to repair the Futenma base on a massive scale as there are no immediate prospects for relocation.

Despite asking Washington to pay for the work, the Japanese side is ready to chip in, the sources said, adding that Tokyo will include the expenses in its fiscal 2013 budget after confirming how the costs will be divided.

Japan has not contributed funding to maintaining key facilities, such as runways and hangars, because the two countries agreed in 1996 to return the base and build a replacement elsewhere in Okinawa, constraining its upkeep.