Turkey has agreed to pay $2.5bn to acquire Russia’s advanced S-400 surface-to-air missile system (the “SA-21 Growler”), a senior Turkish official told Bloomberg on July 13.

The preliminary agreement sees Turkey receiving two S-400 missile batteries from Russia within the next year, and then producing another two inside Turkey, according to the source.

The Russian system would not be compatible with other NATO defence systems, but also would not be subject to the same constraints imposed by the alliance, the official said.

The Russian deal would allow Turkey to deploy the missile defence systems anywhere in the country, the source added.

For Ankara, the key aspect of the deal is transfer of technology, the official said.

“Turkey wants to be able to produce its own advanced defence systems, and the Russian agreement to allow two of the S-400 batteries to be produced in Turkey would serve that aim,” the source told the news service.

According to the Turkish official, Ankara and Moscow are currently sorting out technical details and it could take about one year to finalise the project.

Turkey started talks with China Precision Machinery Import and Export Corp (CPMIEC) on the missile system in September 2013, but opted not to sign the final deal after Nato allies expressed concern over Ankara’s plans to buy the system, citing security and compatibility problems.

Ankara then turned to Russia to buy the anti-aircraft weapon system when in 2015 it cancelled the controversial deal with the Chinese company.

With Ankara and Russia restoring ties, the talks on the missile system have gained momentum.

“In the framework of our project to develop our national defence system project, we will cooperate with France and Italy. This decision has already been taken. We are now in talks with the US to cooperate in this area as well,” Turkish Defence Minister Fikri Isik said on July 4.

Regarding the purchase of the Russian system, Isik admitted that Ankara and Moscow still needed to resolve some financial issues. 

It remains to be seen how Turkey’s Nato allies will react to Ankara’s missile deal with Russia.

The Turkish armed forces are the second largest in Nato, behind those of the US.

Ankara’s relations with two key Nato members, Germany and the US, have deteriorated over the past year.

Washington’s decision to arm and cooperate with the Syrian Kurdish YPG militia in the Raqqa offensive, deeply frustrated Ankara which sees the Kurdish group as a terrorist organisation because of its ties to the Kurdistan Workers’ Party (PKK) which launched an insurgency against the Turkish state in 1984.

Meanwhile Turkey’s relations with Germany have soured especially after the failed coup attempt last year. Ankara accuses Berlin of harbouring some of the coup plotters and members of other terrorist organisations such as PKK.

Bilateral relations hit a new low during the April referendum campaign in Turkey when Erdogan threw "Nazi" jibes at Germany after local German authorities refused to allow Turkish ministers to attend pro-Erdogan rallies to address expatriate voters.

Germany last month decided to pull its troops from Turkey’s Incirlik base after Ankara denied a group of German lawmakers permission to visit more than 250 German troops stationed there.