A contract for the supply of Russia’s advanced S-400 surface-to-air missile system (the “SA-21 Growler”) to Turkey has been agreed, although the issue of loan provision has not yet been settled, Russian presidential adviser for military and technical cooperation Vladimir Kozhin said on June 29, TASS reported.

“The contract has been agreed and everything is understandable there but the issue of a loan, funds has not been settled yet," Kozhin said at the 8th International Maritime Defence Show in St. Petersburg, according to the news service.

Ankara turned to Moscow to buy the long-range anti-aircraft weapon system having in 2015 abandoned a controversial deal with the China Precision Machinery Import and Export Corp (CPMIEC) to acquire the Chinese-built HQ-9 air defence system.

With Turkey and Russia having gradually restored ties following the Turkish air force's shooting down of a Russian fighter-bomber near the Syrian border in late 2016, the talks on the missile system have gained momentum, with Ankara pursuing the hardware despite the fact that its Nato partners might be wary of any move to integrate such Russian technology.

Talks between Turkey and Russia on the procurement of the S-400 had "matured", but the two countries still needed to sort out some pricing issues, Turkish Defence Minister Fikri Isik said on May 10.

On June 3, Sputnik news agency reported that Russia was considering the option of providing Turkey with a loan for the purchase of the missile system.