"The settlements on S-400 systems must be carried out with the use of national currencies. The transfer of these systems to Turkey should be completed by the end of 2019 after which the provision on the settlements with the use of national currencies, which we have suggested from the very beginning, will be implemented by the efforts of finance ministers and central banks of the two countries," Erdogan told reporters before taking off to Argentina for attending the G20 summit, as broadcast by NTV.
In December 2017, Ankara signed a loan agreement with Moscow envisaging the delivery of the Russian-made S-400 air defence systems to Turkey. Russia's Rostec state corporation CEO Sergey Chemezov said then that the contract envisaged the delivery of four S-400 battalion-size sets worth $2.5 billion, with 55 percent of the contract sum being covered by Russian loans.
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In October, Akara said that Turkey would begin the deployment of the S-400s in October 2019.