Tentative reports have emerged in the Turkish press that Turkey is looking at buying Russian Sukhoi Su-57 fighter jets in the event that the US follows through on threats to not deliver Lockheed Martin F-35 Joint Strike Fighter jets to Ankara.

Turkey’s YeniSafak reported on the matter on May 27, saying that Turkey has entered discussions on the possible acquisition of stealth, twin-engine multi-role Su-57s as they are seen as a good alternative given that they are around half the price of F-35s. The level of discussion was not specified. Deliveries of the Su-57 to the Russian Air Force are scheduled to start next year. The newspaper also stated that Turkey has no plans to abandon its right to obtaining F-35s and expected deliveries to begin in June.

Turkey on May 27 vowed a response if a bill passed the previous day by a US Senate committee is adopted as a law that prevents it from purchasing F-35s. If such a ban came to pass, it would be a devastating blow inflicted on one Nato member by another and would almost certainly push Turkey into deeper geopolitical alliances with the Kremlin.

An amendment to the National Defense Authorization Act, or NDAA, from Democratic Senator Jeanne Shaheen and Republican Senator Thom Tillis, would if actioned remove Nato member Turkey from the F-35 programme over its detention of US citizen and pastor Andrew Brunson. The bill also finds fault with Turkey’s plan to buy the advanced S-400 missile defence system from Russia. US Secretary of State Mike Pompeo on April 29 told Turkish counterpart Mevlut Cavusoglu that the US is seriously concerned by Ankara’s decision to buy the hardware, which is not compatible with systems used by Nato countries.

Turkish foreign ministry spokesperson Hami Aksoy was quoted as saying by Hurriyet Daily News on May 25 that preventing the sale of F-35s to Turkey would be “against the spirit of [Turkey’s] alliance with the US”. “This is not a programme managed solely by the US. It is a multinational program and we expect everybody to fulfil their obligations,” Aksoy reportedly added. Turkey, he said, has “fulfilled its obligations” in regard to the F-35 programme and if the US moved to bar the supply of F-35s “we will have to respond”.

Brunson, a Christian pastor, could be jailed for up to 35 years, if he is found guilty of terrorism and spying charges which he has denied.

In regard to Ankara’s planned S-400 purchase, Senator Shaheen said: “There is tremendous hesitancy [when it comes to] transferring sensitive F-35 planes and technology to a nation who has purchased a Russian air defence system designed to shoot these very planes down.”

Turkey plans to buy more than 100 F-35 jets.

On April 23, it was reported that the future maintenance of the UK’s F-35 fighter jets might be put at risk by Washington’s displeasure with Ankara over its planned purchase of the Russian S-400 anti-aircraft systems.

The Register reported: “US government official Aaron Wess Mitchell threatened action if the Middle Eastern/ European nation completed its purchase of Russian S-400 anti-aircraft defence systems, according to Flight Global, which reported the assistant secretary of state for European and Eurasian affairs as saying during a US Congress session: ‘This is because Turkey is an F-35 customer. Testing F-35s against a Russian-made air defence system inevitably raises fears that vital information on neutralising the F-35 threat would then be handed to the Russians on a plate.’”

The NDAA is several steps from becoming law. To confirm it as passed legislation, the Senate must still pass its version of the bill which must be reconciled with a House of Representatives version before a final compromise bill goes through for a vote in both the House and Senate later this year.