The Pentagon wants the F-35 to replace most of its ageing fighter jets.

US Defence Secretary Robert Gates has sacked the marine general overseeing a $40bn (£25bn) project to build the next generation strike fighter jet.

F-35 programme chief Maj Gen David Heinz will be replaced by a yet to be named higher ranking general.

Mr Gates said the F-35 programme had been plagued by problems and failed to hit performance targets.

He also said Lockheed Martin, the US firm making the jet, would not receive $614m in performance-related payouts.

The Pentagon wants the F-35 to replace most of its ageing fighter jets.

"The progress and performance of the F-35 over the past two years has not been what it should," Mr Gates told a news conference on the Pentagon's proposed budget.

He added that "a number of key goals and benchmarks were not met".