The United States was told last week that an offshore airport designed to be the relocation site for the U.S. Marine Corps Futenma Air Station in Okinawa would take 9 1/2 years to build, not including land reclamation work, Japanese officials said Wednesday.

A senior official at the Defense Facilities Administration Agency said the joint military-civilian airport's main facilities, off the Henoko district of Nago, northern Okinawa, would be finished in the period.

Earlier projections had put the time frame at more than 10 years. Construction, however, has yet to start.