The US Department of Defense has awarded a $571m contract to Pratt & Whitney to supply F135 engines for the F-35 Lightning II joint strike fighter aircraft.

The F-35 programme involves the development and production of a fifth generation of stealth fighters that will be delivered to the US Air Force and eight allied countries.

The low rate initial production contract covers production, sustainment, spare parts and engineering support for the third lot of engines, including ten for conventional take-off and landing and 11 for short-takeoff/vertical-landing F-35s.

In addition, the USAF has awarded $113m for long lead material procurement to produce 32 F135 engines for the fourth lot.