The shortfall was revealed in a new list of unfunded priorities sent to Congress, the report said on Tuesday.
If the $1.4 billion is not additionally provided, the anticipated new three-year contract worth up to $30 billion will go ahead, but it will purchase fewer aircraft for the expensive program, whose total cost is now estimated at $412 billion, the report said.
The Defense Department and Lockheed Martin are reportedly in the final stages of negotiating a contract for 375 aircraft in the F-35’s 15th through 17th production lots but because of the shortfall, less aircraft are likely to be ordered, the report said.
The current figure was already 110 aircraft short of the 485 F-35 jets originally anticipated in February 2019, the report added.
This latest shortfall has been caused by higher per-aircraft costs due to COVID-19 pandemic measures, supply chain disruptions, inflation and a reduction in procurement quantities compared to the previous F-35 contract, according to Defense Department F-35 Office spokesperson Russell Goemaere.