The Department of Defense urged the Netherlands on Thursday not to cut its order for advanced F-35 warplanes, saying it could end up paying more per plane if it did.
Fearing that major cuts to orders could ultimately doom the delayed and over-budget $400 billion F-35 Joint Strike Fighter project, U.S. officials have been stepping up pressure on buyers to stick to their initial undertakings.
The Dutch government is expected to scale back its order of 85 planes to between 52 and 68, according to people close to the discussions. Purchase plans are due to be finalized this year.
U.S. Air Force Lieutenant General Christopher Bogdan, the head of the Pentagon's F-35 program, told the Dutch parliamentary defense commission it was best for the Netherlands to stick to the original plan.
"If you take airplanes out of the production line today, that will have a great impact on the price of the airplane," he told the commission in The Hague.
But he said the timing of any cancellations was also critical and there would be "very, very little impact" on price if orders dropped were from 2022 to 2024 rather than earlier.
The F-35 program, hit by technical faults, is seven years behind schedule and 70 percent above cost estimates.
U.S. officials fear any cancellations could force up prices for remaining buyers, meaning they are more likely to cancel too.
The Dutch coalition government which took office in November is concerned at the cost of the planes, to replace older F-16 fighters, and is still shaping its defense strategy.
Built by Lockheed Martin Corp , the F-35 is designed to be the next-generation fighter for decades to come for U.S. forces and their allies.
Some Dutch politicians question whether to go for an alternative such as Saab AB's Gripen, Boeing Co's F/A-18 E/F Super Hornet, or the EADS Eurofighter.
A Lockheed Martin official addressed the Dutch defense commission on Wednesday and rivals are also going to make their case.
In new estimates that will be scrutinized by arms firms worldwide, Bogdan said the warplane would cost $85 million in 2020 and the F-35A air force version would cost $23,900 per hour to fly compared with $21,500 for the older F-16s.
Washington itself has delayed 410 of its 2,443 orders for F-35s beyond 2017.
(Additional reporting by Tim Hepher; Editing by Matthew Tostevin)