Israeli politician Yair Lapid on Saturday challenged the U.S. to boot Turkey from the F-35 stealth fighter program for taking delivery of advanced Russian air defense systems in defiance of U.S. warnings.

Russia’s S-400 is considered one of the most advanced and feared air-defense systems in the world.

The U.S. has long argued Turkey’s purchase of the Russian system not only risks the security of NATO members, it also violates the 2017 law threatening sanctions for any purchase of sophisticated Russian technology — the Countering Russian Influence in Europe and Eurasia Act of 2017.

“The US has to cancel the F-35 deal with Turkey, otherwise nothing will stand in Turkey and Iran’s way as they learn how to neutralize America’s most advanced weaponry,” Lapid tweeted.

As I warned members of Congress this past year, Turkey has ignored all threats and purchased the S400 system. The US has to cancel the F-35 deal with Turkey, otherwise nothing will stand in Turkey and Iran’s way as they learn how to neutralize America’s most advanced weaponry. — יאיר לפיד Yair Lapid (@yairlapid) July 13, 2019

The Blue and White party No. 2, a vocal critic of Turkish President Recep Tayyip Erdogan, said he had warned U.S. congress about Turkey’s controversial purchase of the S-400 system.

The Times of Israel reports ties between Israel and Turkey have been fraught since Erdogan’s ascension to power. Lapid has chided PM Netanyahu for not taking a firmer stance toward Turkey’s leader, who is known for lobbing broadsides at Israel.

Turkey began to receive the S-400 air-defense missile-defense system on Friday despite U.S. warnings not to do so.

CNN reported “TASS also quoted the source saying that Turkish S-400 operators will travel to Russia for training in July and August. About 20 Turkish servicemen underwent training at a Russian training center in May and June, according to the source.”

The United States suspended the delivery of F-35 warplane-related equipment to fellow NATO member Turkey in April, warning Ankara to abandon its scheduled purchase of the Russian missiles.

On the evidence it appears Turkey has no intention of heeding Washington.