Russia will start delivering its S-400 missile defense systems to Turkey in July, the head of Russian state arms exporter Rosoboronexport said, according to Interfax news agency."Everything has been already discussed and agreed," Alexander Mikheev told Interfax.The United States has threatened to impose sanctions if Turkey seals its S-400 deal with Russia. Ankara has said its purchase should not trigger sanctions as Turkey is not an adversary of Washington and remains committed to the NATO alliance. The top uniformed officer in NATO and the head of American forces in Europe, General Curtis Scaparrotti warned in March during testimony to the Senate Armed Services Committee that Ankara’s purchase of the S-400 presents a problem to all American aircraft, including the stealth F-35 fighter jet.“My best military advice would be that we don’t then follow through with the F-35 — flying it or working with an ally that is working with Russian systems, particularly air defense systems, with one of our most advanced technological capabilities,” Scaparrotti was quoted by Defense News as saying.The deterioration of ties between Ankara and Washington led US lawmakers to voice concern that if Russia provides the S-400 to Turkey while it flies the F-35, the capabilities and vulnerabilities of the jet could potentially be conveyed to Russia, compromising it to all partner nations flying the plane.Israel, which also has fragile relations with Turkey, currently has 14 F-35 Adir aircraft and is expected to receive a total of 50 planes to make two full squadrons by 2024.According to foreign reports, Israel has already quietly tested ways to defeat the advanced Russian air defense system, participating in several joint drills with the Greek Air Force over the island of Crete where one system is stationed. The drills have reportedly allowed Israeli warplanes to gather data on how the advanced system may be blinded or fooled.