“Practically speaking, the contract is entering the phase of realization,” said Vladimir Kozhin, a presidential aide who oversees matters of military cooperation.

“All parameters, all technologies, the entire deal has been agreed,” said Kozhin.

“All aspects have been resolved over the past few days. The contract will consist of two parts financially: part of it will be paid by Turkey and part through a credit provided by Russia,” said the Russian presidential aide, Anadolu news agency reported.

“The first deliveries are likely to begin at the end of 2019, beginning of 2020,” Kozhin was reported as saying by Russian news agencies.

Russia’s President Vladimir Putin and his President Recep Tayyip Erdogan had discussed the deal during Putin’s visit to Ankara last week.

The agreement to purchase the latest Russian surface-to-air missile defense batteries is Turkey’s most significant deal with a non-NATO military supplier, and comes amid strained relations between Ankara and several Western countries.

The deal has been valued at about $2 billion according to reports.

Turkey’s decision to buy the Russian system has raised eyebrows of other NATO members, with the Pentagon saying previously that “generally it’s a good idea” to buy equipment that is inter-operable with the military alliance’s other systems.

Reporter’s code: 50101