The US government obligated $2.18 billion in funding from Foreign Military Sales (FMS) customers and international partners in the Joint Strike Fighter programme for an interim contract to Lockheed Martin to continue F-35 production.

The award funding 50 international aircraft was expected, following a 7 July agreement known as an "undefinitised contract action" (UCA) that continued domestic aircraft production.

The F-35 Joint Programme Office (JPO) values the latest award at $2.18 billion, although it had previously valued the contract at $2.28 billion. The office did not respond to a request to explain the difference.

The UCA, which has a $5.57 billion price ceiling, allows Lockheed to continue producing F-35s until the programme's low-rate initial production (LRIP) Lot 11 contract is finalised. Ultimately, LRIP 11 will include 91 jets for the US armed services, plus 28 for international partners and 22 FMS aircraft for export buyers.

“The US Department of Defense will continue to negotiate the LRIP 11 contract with Lockheed Martin, and expects to definitise by the end of the year,” the DoD said on 28 July. “We are confident the final negotiated Lot 11 aircraft unit prices will be less than Lot 10, and represent the best interests of the government and provide acceptable profit to the contractor.”

Separately, the DoD and F135 engine manufacturer Pratt & Whitney are negotiating the F-35 programme's Lot 11 propulsion contract. The JPO says it also expects to wrap-up negotiations on both this award before the end of 2017.