WASHINGTON — Sen. Lindsey Graham said Friday he didn’t believe Defense Secretary Robert Gates’ get-tough ultimatum to contractors building the troubled -35B jet fighter threatened the arrival of five squadrons in Beaufort.

Graham responded to Gates’ announcement Thursday of sweeping Pentagon program cuts.

Gates wants to give Lockheed Martin, which has the main defense contract for developing the Marine Corps’ version of the Joint Strike Fighter, two years to improve software guiding its short takeoff and vertical landing capability.

Despite delays and cost increases that have doubled the jets’ cost to $100 million apiece, Graham expressed confidence Marine Corps Air Station Beaufort will receive the five squadrons of F-35B’s it’s slated to get by 2015.

“I believe that the F-35’s we’re due to receive are already accounted for,” Graham told McClatchy.

Gates was less sanguine about the jet fighter’s prospects at a Pentagon briefing.

“If we cannot fix this (software) variant in this two-year timeframe … then I believe it ought to be canceled,” he said.

The Beaufort air station is slated to host three new active-duty Joint Strike Fighter squadrons and two pilot-training squadrons, or a total of 88 of the aircraft.

In North Carolina, eight squadrons of F-35B’s are scheduled for delivery to Marine Corps Air Station Cherry Point.

Gates’ touch stance on the jet fighters comes just one month after the Navy announced plans to put the 13 combined squadrons at the two Carolinas stations.

The Joint Strike Fighter jets are expected to replace the F-18 Hornets now flown at the bases.

Marine Corps Commandant Gen. James Amos last month shelved plans for the F-35B to be ready for combat by the end of next year because of flight-test delays caused by parts shortages and other problems.

Both stations in the neighboring states have started multimillion-dollar construction projects to upgrade and build facilities for housing the new fighter jets.

Almost $352 million in improvements are slated for the Beaufort station, among them a pilot-training center, new hangars, flight simulators and special pads for the aircraft’s vertical landings and takeoffs.

For all the problems, Graham still expects to see the five F-35B squadrons find a home as planned in the Lowcountry.

“I have not been told anything to suggest that the squadrons assigned to Beaufort are going to change,” Graham said.

( McClatchy reporters Patrick Donohue, Barbara Barrett and Nancy Youssef contributed to this account)