Russia is to offer Turkey partial financing for Ankara’s acquisition of S-400 surface-to-air missile systems, Interfax news agency quoted a Russian presidential aide as saying on December 12.

“Technical questions are under discussion, the interest rate. Everything is at the Finance Ministry,” the aide, Vladimir Kozhin, reportedly said of the deal.

Turkish President Recep Tayyip Erdogan on December 11 anticipated that the deal to purchase the S-400 advanced military hardware would be concluded within days. “Our officials will come together in the coming week to finalise the S-400 issue,” Erdogan said at a joint news conference held with Russian counterpart Vladimir Putin, who was on a whirlwind tour of the Middle East.

Turkey has been in talks with Russia to purchase the anti-aircraft system for more than a year. That has unsettled NATO allies who see the move as somewhat provocative—particularly given the backdrop that has seen Ankara grow geopolitically closer to Moscow and less aligned with Washington and the EU because of a series of rows tied to Turkey’s governance and demands under its continuing state of emergency—because the system cannot be integrated into the military alliance’s defences.

Independence in military equipment production is an objective Turkey wants to meet within a few years. It is developing domestic projects that are to produce combat helicopters, drones, tanks and other defence items.

Turkey expects to receive its first S-400 system in 2019. The drawn up deal includes two systems, with one optional.