WASHINGTON (AP) -- U.S. Air Force Secretary Michael Donley said Tuesday that the service's plan to use the Pentagon's marquee fighter jet, the F-35 Joint Strike Fighter, will probably be delayed by two years and cost significantly more than initially expected.
Donley told reporters the F-35 is not likely to be ready for the Air Force until 2015.
The jet had been scheduled to become initially operational in 2013 before the Pentagon uncovered serious problems with the contract. Last month, Defense Secretary Robert Gates announced that at least one senior manager would be fired and $614 million in performance bonuses would be withheld from lead contractor Lockheed Martin Corporation.
"We remain fully committed to this program," Donley said.
But waiting until late in the 2015 budget year for the jet to reach a milestone known as initial operating capability is "the best estimate today on where we'll be," he added.
The delay suggests the program's problems were perhaps deeper than officials expected. When Gates discussed the program last month, he said he thought the early production milestone would remain intact.
Donley said that when Gates made his remarks, the service was still working through detailed reviews of the program.
He said problems are being addressed. "We want to hold the contractors' feet to the fire," he said. "We want to incentivize them to make good on the promises they made earlier and deliver on schedule."
Britain is expected to acquire the F-35 and other U.S. allies have expressed interest in joining the program.