Russia and Turkey are in talks about the possibility of jointly manufacturing some components of Russia's S-400 missile defense system in Turkey, the TASS news agency cited Sergei Chemezov, head of Russia's Rostec state conglomerate, as saying.

Turkey began receiving deliveries of Russian S-400 systems earlier this month, prompting the United States to begin suspending Turkey from its F-35 stealth fighter program over security concerns.

TASS said Chemezov's comments were originally made to Turkey's Anadolu news agency.

Following protracted efforts to purchase an air defense system from the U.S. with no success, Ankara decided in 2017 to purchase the Russian S-400 system.

After the purchase, U.S. officials advised Turkey to buy the U.S. Patriot missile system rather than the S-400s, arguing the Russian system would be incompatible with NATO systems and expose the F-35 to possible Russian subterfuge.

But Turkey has emphasized that the S-400s would not be integrated into NATO operability and would not pose a threat to the alliance. It has also repeatedly said it was ready to discuss Washington's concerns. It proposed forming a joint working group with Washington to assess whether the S-400s would pose a threat to NATO; however, the U.S. has not taken any steps to form the technical team.

The White House said Wednesday that it was no longer possible for Turkey to be involved in the F-35 program after parts of S-400 began arriving in Ankara. The U.S. also said it would impose sanctions on Turkey under the Countering America's Adversaries Through Sanctions Act (CAATSA), which aims to prevent countries from purchasing military equipment from Russia.

Foreign Minister Mevlüt Çavuşoğlu said Monday Turkey would retaliate if the U.S. imposes sanctions and that Ankara would consider alternatives to F-35 if Washington went ahead with expulsion.

The delivery of S-400 components began in the second week of July and is ongoing, with over a dozen shipments of related equipment landing in Turkey so far.