Russia will begin delivering its advanced S-400 missile defense system to Turkey in 2019, according to Interfax news agency.
A Turkish defense official said in April that the delivery of S-400 batteries had been anticipated from the first quarter of the 2020 in July 2019.
Turkey and Russia negotiated the purchase throughout 2017, concluding a deal worth around $ 2,5 billion at the end of the year. Turkey's purchase of the air defense system created in Russia has increased tensions between Ankara and the rest of the NATO alliance.
The missile system is not interoperable with NATO weapon systems. A Turkish official said last year that the S-400 will not have a friend-foe identification system, meaning it could hit any target. In September, Turkey's state-run media agency tweeted an infographic listing the aircraft and missiles the S-400 could target, including NATO aircraft.
The US has also expressed concern that Turkey's deployment of the S-400 could jeopardize the safety of several US-made weapons used by Turkey, including the Joint Strike Fighter F-35.
US lawmakers have included a provision in the National Defense Authorization Act of 2019, signed by President Donald Trump, that prevents delivery of the F-35 to Turkey until the Pentagon completes an assessment of US-Turkish relations and the effect of Ankara's purchase of the S-400.
Turkey has already received two of the approximately 100 F-35s it was supposed to purchase, and the measure that blocked further deliveries came following objections from Defense Secretary Jim Mattis. Turkey has said it will pursue international arbitration on blocking the sale of F-35s.
Turkey is not the first foreign buyer of the S-400. China entered into an agreement with Rosoboronexport in late 2014 to upgrade its current S-300 batteries with the S-400 system.
Turkey may not be the latest US partner to frustrate Washington with S-400 purchases. India's defense minister said in July that New Delhi's plan to purchase the S-400 was in an "almost final phase". Saudi Arabia and Qatar also seem to be considering buying it.