WASHINGTON, DC — The United States should refuse to sell its high-tech F-35 warplane and other weapons systems to NATO ally Turkey if Ankara moves forward with the purchase of the S-400 missile system from Russia, Gen. Curtis Scaparrotti, the head of U.S. European Command (EUCOM), suggested this week.

During a Senate Armed Services Committee hearing on Tuesday, Scaparrotti, who also serves as NATO’s supreme allied commander in Europe, urged Turkey to reconsider its plan to purchase the S-400 system from the Kremlin this year or “forfeit” future sales of American military aircraft and systems.

Echoing other American and NATO officials who have advised against the purchase of the Russian weapons, the top U.S. general cautioned that the surface-to-air missile defense system would be present a threat to the F-35, noting that it is not compatible with other allied systems and would ultimately threaten security.

Asked whether or not Turkey should receive the delivery of the F-35s if Ankara moves forward with the purchase of Russia’s S-400 system, Gen. Scaparrotti replied:

If they accept the S-400…there’s first of all an issue that it’s not interoperable with NATO systems nor is it interoperable inside of our integrated air missile defense system so that presents one problem.

The second [problem] has to do with the F-35. It presents a problem to all of our aircraft but specifically the F-35 I believe, and my best military advice would be that we don’t [ proceed with the sale of the aircraft].

Scaparrotti stressed that U.S. officials are warning Turkey against the potential consequences of the S-400 purchase, telling lawmakers:

This is a huge decision for Turkey and we’ve continuously — I’ve talked to them personally as…all of our leadership has…[and] I would hope that they would reconsider this one decision on S-400, one system, [or] potentially forfeit many of the other systems…that we provide them.

In a speech in Munich last month, U.S. Vice President Mike Pence declared that the Trump administration has “made it clear that we will not stand idly by while NATO allies purchase weapons from our adversaries.  We cannot ensure the defense of the West if our allies grow dependent on the East.”

Although the U.S. has already delivered two warplanes under an agreement to sell F-35 fighter jets to Turkey, Congress ordered a delay in future deliveries last year.

The U.S. Department of State (DOS) approved the sale of a $3.5 billion Patriot missile defense system to Turkey in December, Voice of American (VOA) acknowledges.

NATO member Turkey intends to proceed with the purchase of the S-400 missile despite U.S. warnings and the sale of the American-made system, claiming it will grant the United States personnel access to the Kremlin weapon.

The top American and NATO commander in Europe cautioned:

While the United States maintains global military superiority over Russia, evolving Russian capabilities threaten to erode our competitive military advantage, challenge our ability to operate uncontested in all domains and diminish our ability to deter Russian aggression.

Gen. Scaparrotti, told lawmakers he needs more troops, ships, and improved intelligence, surveillance, and reconnaissance (ISR) capacity to combat rising Russian aggression.

He emphasized that EUCOM lacks the proper posture and capabilities to deter Russian aggression in Europe, citing manpower and naval capabilities shortfalls.