Russia said Thursday that it had completed negotiations with Turkey for the sale of an S-400 air defence missile system, with delivery scheduled for late 2019.

“Practically speaking, the contract is entering the phase of realisation,” said Vladimir Kozhin, a presidential aide who oversees matters of military cooperation. “All parameters, all technologies, the entire deal has been agreed.”

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

“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 Turkish counterpart Recep Tayyip Erdogan had discussed the deal during Putin’s visit to Ankara last week.

The deal has been negotiated since the summer, with a Turkish priority being the transfer of technology and joint production. The agreement was officially signed only in September, when Ankara made an advance payment. Turkish Foreign Minister Mevlut Cavusoglu said in October that Turkey could annul the S-400 deal if Moscow refuses to transfer technology.

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.

However, Turkey is not going to rely solely on the S-400 for air defense. Turkish Defense Minister Nurettin Canikli said on November 12 that Turkey agreed with Eurosam to develop an air defense missile system and to own the technology with Turkey’s “own local resources.” The previous day, Canikli signed a letter of intent with the defense ministers of France and Italy, paving the way for Turkey’s purchase of the Eurosam SAMP-T launcher systems and Aster 30 surface-to-air missiles.

Besides Turkey, Russia is also in talks to sell the S-400 system to Saudi Arabia, with Kozhin saying Thursday that both sides were aiming to finalise the remaining issues on that contract before the end of the year.

With reporting from AFP