(FILES) In this file photo taken on September 22, 2020 A rocket launches from a S-400 missile system at the Ashuluk military base in Southern Russia during the "Caucasus-2020" military drills gathering China, Iran, Pakistan and Myanmar troops, along with ex-Soviet Armenia, Azerbaijan and Belarus. The United States on December 14, 2020 imposed sanctions on Turkey's military procurement agency after the NATO ally defiantly bought Russia's S-400 air defense system. / AFP / Dimitar DILKOFF
The Russian-made S-400 missile system in action. The US announced on Monday it would be issuing sanctions against Turkey for its controversial purchase of the missile defence system in 2017. AFP

US sanctions against Turkey were inevitable