The Aug. 6 missile and drone attack across Ukraine killed six people, Kyiv officials said. Ukrainian President Volodymyr Zelenskyy said the Zaporizhzhia-based facilities of Motor Sich, which his government took over in November, also came under attack.

The privately owned business Baykar builds the Akinci and Kizilelma drones, for which Motor Sich provides engines.

Eugene Kogan, a security and defense analyst based in Tbilisi, Georgia, said Russian President Vladimir Putin was essentially telling his Turkish counterpart Recep Tayyip Erdoğan: “Despite our friendly relations and respect to each other, your son-in-law’s undertaking in Ukraine will cost him dearly” — a reference to Baykar chairman Selcuk Bayraktar, who is married to one of the Turkish president’s daughters.

“Any military facility in Ukraine, local or foreign, is a legitimate target, and Russia is not going to be deterred by Ukraine to destroy such targets,” Kogan added.

Motor Sich and Ukrainian firm Ivchenko-Progress have been providing AI-450 engines for the Akinci drone, as well as AI-25TLT engines for the Anka-3 and Kizilelma drones. Turkish Aerospace Industries produces the Anka-3, and Baykar’s Kizilelma is still under development.

Motor Sich engines also power Turkish Aerospace Industries’ Atak II heavyweight combat helicopter. And talks were underway for a Motor Sich engine to power the T925, TAI’s utility helicopter. It’s unclear where negotiations now stand.

In 2019, LLC Avia Ventures, a Baykar subsidiary, obtained permission to produce its Akinci and TB2 drones in Ukraine, with work to start in 2025. In January of that year, Baykar won a $69 million contract to sell six TB2 systems to Ukraine.

Later that year, state-controlled Ukrainian company Ukrspecexport and Baykar signed a deal to develop and produce “sensitive technologies in defense and aerospace.”

And in 2021, Turkey and Ukraine signed a contract to establish a helicopter repair and maintenance facility in Ankara. As part of the deal, Motor Sich would provide spare parts and engine testing services.

Baykar and TAI did not reply to Defense News’ queries.

“We take it [the Russian missile attack on Motor Sich] as a symbolic Russian warning reflecting Russia’s discontent over a few Turkish initiatives,” a senior Turkish diplomat told Defense News on the condition of anonymity due to the sensitivity of the topic.

While Turkey is a member of NATO, it has maintained friendly relations with Russia. In 2017, Turkey bought the Russian-made S-400 air defense system, angering members of the Western alliance. But last month, Erdoğan met with Zelenskyy and backed Ukraine’s hopes of joining NATO.

Ozgur Eksi, an Ankara-based analyst, said the Aug. 6 attack “is a message both to Ukraine and to Turkey.”

“The Russian attack effectively kills co-production plans and any Turkish appetite to buy Motor Sich,” Eksi told Defense News.

A Turkish procurement official said the country has enough Ukrainian-made engines on hand to run, among others, its drone programs uninterrupted. The official was not authorized to speak to the press, and Defense News could not independently verify the claim.

However, Eksi said, “this may be a short-term solution, but not a relief from a long-term perspective.”

The Associated Press contributed to this report.

Turkey initially purchased the S-400 in 2017, plunging its relationship with the U.S. into crisis. As a result of the deal, the Trump administration expelled Turkey from the F-35 program and later sanctioned the country’s defense industry organization and its leaders. The United States fears the powerful S-400 radar system would allow Russia to spy on the advanced F-35 fighter jet.

But the reaction in the U.S. on Tuesday was comparatively muted. At a press briefing, State Department spokesman Ned Price urged Turkey not to further engage with Russia’s defense sector.

“The point that we have consistently made across the board is that Russia’s brutal and unjustified war against Ukraine makes it vital, now more than ever in some ways, that all countries avoid transactions with Russia’s defense sector,” he said.

“We’ll have to wait and see what happens, but we are not aware of any new developments on this matter,” Price added.

Price declined to address whether a new S-400 would prompt the Biden administration to reconsider plans to sell F-16 fighter jets to Turkey.

The Russian news agency TASS reported Tuesday Russia and Turkey have signed a contract for a second “regiment” of the S-400 to Turkey, quoting the head of the Federal Service for Military-Technical Cooperation, Dmitry Shugayev.

Turkish defense sources quickly rebutted Russian claims it had signed an additional contract, noting the second S-400 was part of the initial agreement.

Shugayev, the Russian official, reportedly told TASS the new agreement with Turkey will allow for some components of the system to be built in Turkey.

Turkish sources told Defense News there may be an agreement with Russia to domestically manufacture some S-400 components for the second regiment.

The Turkish Embassy in Washington didn’t return a request for comment.

Turkey’s complex balancing act between the West and Russia has only gotten trickier since Russia’s invasion of Ukraine. The strongest sign of a thaw between Turkey and the U.S. came in late June as Turkish leader Reccep Tayyip Erdogan dropped objections to Finland and Sweden joining NATO.

U.S. President Joe Biden then voiced support for the F-16 sale at the NATO summit in Madrid in June.

A delegation from Ankara arrived in the U.S. on Monday for the fourth round of technical talks with Washington on a potential F-16 deal, Turkey’s Anadolu Agency reported this week.

Turkey has asked to make a $6 billion purchase of 40 Lockheed Martin Block 70 F-16 fighter jets. It is also seeking a separate $400 million sale to upgrade their current F-16 jets with new missiles, radar and electronics.

Senate Foreign Relations Committee Chairman Bob Menendez, D-N.J., has threatened to block the F-16 sale over Turkey’s continued possession of the S-400s, its violations of Greek airspace and Cypriot waters in the eastern Mediterranean, its human rights record and ongoing attacks on U.S.-backed fighters in northeast Syria.

Menendez issued a statement on Thursday blasting reports that Turkey intends to proceed with the second S-400 batch and called on Ankara to “unequivocally demonstrate its commitment to NATO and to regional peace and security by fully rejecting any military cooperation with a war criminal like Vladimir Putin.”

“Between continued antagonistic violations of Greece’s airspace and the delaying of the accession process for Sweden and Finland’s NATO membership, I sincerely hope Turkey will change course and live up to its responsibilities to the defense alliance by being the constructive partner in the region we all hope it can be,” said Menendez. “The United States must be clear: Any expansion of Turkey’s ties to the Russian defense sector would be a grave mistake that would further endanger the security of our NATO allies and partners throughout Europe.”

Despite increased tensions with its NATO allies in recent years, Turkey has generated some goodwill in Washington over its support for Ukraine against Russia. Turkish firm Bayraktar has been selling Ukraine its TB2 laser-guided, bomb-dropping drone for use against Russian troops, and, in June, Ukraine said Bayraktar would open a drone factory within its borders to help repel the invasion.

In recent weeks, Erdogan also brokered an international deal with Russia to allow the export of grain from Ukraine, a breadbasket for the world, to ease a global food crisis. Agricultural goods had been stuck in Black Sea ports due to the invasion.

Eric Edelman, a former U.S. ambassador to Turkey and senior Pentagon official, said he believes the S-400 deal between “competimates” Erdogan and Russian President Vladimir Putin will confound efforts to mend ties between Turkey and the U.S.

“To say the least, this will complicate the Biden administration’s effort to sell F-16s to Turkey and enrage Turkey’s growing legion of detractors on Capitol Hill,” Edelman said.

Jim Townsend, the Pentagon’s top Europe and NATO policy official during the Obama administration, said he doubts the S-400 deal came about without Turkey giving advanced warning to the U.S. He hypothesized that it was a component of the international grain deal.

“This might be residue from that deal, and if that is the case, then we probably heard about it, not only because we were probably in the background of these discussions, but also so that the Turks don’t have to pay a price from the U.S. for doing something to make the grain deal work,” Townsend said.

The hushed U.S. reaction to the Russian report is a clue, he added.

“If we’re not thundering from the pulpit, we probably knew about it,” Townsend said.

Separately, the Turkish government congratulated Trump for his presidential victory while repeating its call for the extradition of US-based Islamic preacher Fethullah Gulen, accused of orchestrating the failed coup attempt of July 15.

Prime Minister Binali Yildirim said: “We congratulate Mr. Trump. I am openly calling on the new president from here about the urgent extradition of Fethullah Gulen, the mastermind, executor and perpetrator of the heinous July 15 coup attempt, who lives on US soil.” The prime minister said Gulen’s extradition could mark a new beginning in U.S.-Turkish relations.

“I am sure that the strategic partnership of Turkey and the US, which is based on a long history, has created an opportunity for the new president, paying attention to Turkey’s sensitivity in the fight against terrorism, carrying forward traditional friendly relations, [and] prioritizing peace and security in the region,” Yildirim added.

Turkey has been vehemently demanding Gulen’s extradition from the US since the failed putsch of July 15. Gulen, once a staunch political ally of Erdogan, has been living in self-exile in Pennsylvania since 1999.

Procurement officials in Ankara said the future of defense cooperation would largely depend on whether Trump would favour a policy for more technology transfers to Turkey.

“We do not think Trump’s election will be an immediate game-changer in procurement ties,” one official said. “Over time, however, we would expect him to pursue a policy to share more with NATO ally Turkey.”