Turkey has mentioned the mysterious S-500 system before. In June 2018, Press TV in Iran noted that Erdogan had offered to jointly produce a “new generation S-500 high-altitude missile defense system” with Russia. Anadolu news noted in March that the system was being explored, noting that it “is considered more advanced.”

Turkish President Recep Tayyip Erdogan said that Turkey had finalized its S-400 deal with Russia and would not turn back from acquiring the advanced system. In comments made Saturday, the Turkish leader also hinted at producing an “S-500” system with Russia. This would be a major element of the emerging Turkish-Russian alliance, and another sign of Ankara’s drift away from the US and NATO.

Russia’s TASS news agency says that Russian officers have been training to use the system, which is supposed to be “the backbone of Russia’s integrated air defense and missile defense system.” The report noted that according to Russian Defense Minister Sergei Shoigu, the S-500 is equipped with missiles that can target planes, drones and ballistic missiles.

But TASS oddly relies on Western media reports to assert that it can hit distances of 481 km. The system, which is still under trial, should be ready by 2020. TASS also reported that Turkey wanted to produce the system in cooperation with Russia.

The decision by Ankara to further its defense cooperation with Moscow will be another hurdle to US-Turkish relations. The S-400 deal has already caused a crisis, and reports that Turkey might help produce the S-500 illustrate how close Ankara and Moscow are. Previously, Turkey had played a role in developing the US F-35 fighter jet, but the acquisition of the S-400 has raised concerns in Washington. Yet Erdogan has said that Turkey will eventually receive the F-35.