Israel's air force has tested new versions of some of the locally-made weapon systems that will be carried by its Lockheed Martin F-35s.

Specifics of the adaptations have not been disclosed, but the list includes versions of Rafael's Spice precision-guided bombs and infrared- and radar-guided air-to-air missiles. Testing has been conducted using Boeing F-15s and Lockheed F-16s.

Israel's first pair of conventional take-off and landing F-35A Adirs are scheduled to arrive on 12 December. The aircraft will then be equipped with additional electronic systems, enabling the fast processing of a large volume of real-time intelligence data.

"The Israeli air force's F-35s will have operational capabilities that are unique and tailored to answer Israeli needs," a service source notes.

Another six of the nation's new stealth fighters will be delivered in 2017, with the remaining 25 on order and due to follow over several years.

Meanwhile, the US administration has reiterated its promise to not sell the F-35 to other nations in the Middle East region for "the foreseeable future", in order to maintain Israel's future advantage in operating the advanced type.