MOSCOW, October 25. /TASS/. Around 100 Turkish military servicemen will undergo instruction in the operation and maintenance the S-400 systems at a training center in Russia in the autumn of 2019, a military-diplomatic source informed TASS on Thursday.

"It is planned that around 100 Turkish military servicemen will arrive at the Russian Defense Ministry’s training center in Gatchina, near St. Petersburg, in September or October 2019, where they will undergo training for five months in the operation and maintenance of the S-400 systems, which will be delivered to Turkey almost simultaneously with the beginning of their training course," he said.

The air defense system will be equipped with a Russian-manufactured NATO-compatible friend-or-foe interrogator, which will guarantee their operation within NATO’s air defenses,the source said.

"At Turkey’s request the S-400 systems being supplied will be equipped with friend-or-foe interrogators of Russian manufacture compatible with NATO standards. When the systems are delivered to Turkey, Turkish specialists will insert blocks with NATO codes and letter-designated frequencies," the source said.

According to him, the deal does not include licensed production of missiles by Turkish manufacturers.

"The S-400 deal only includes deliveries; there is no provision on the transfer of technologies or licensed production in Turkey. The equipment will be delivered in an assembled state," the source stated.

The source added that the S-400 missiles would be equipped with a NATO-approved transponder allowing for alignment with the NATO air defense systems.

Turkish Defense Minister Hulusi Akar stated earlier that Ankara would begin the deployment of the Russian-made S-400 air defense systems in October 2019, adding that Turkey had started recruiting military personnel to maintain the complexes.

A military diplomat told TASS earlier that Russia’s defense companies had been tasked to complete the production of the S-400 systems for Ankara in May 2019. Turkey has become the second foreign buyer of the S-400 systems after China. An official announcement about the signing of a contract on the delivery of the S-400 systems was made in September 2017. Initial plans said that the systems would be handed over to Turkey in early 2020 but Ankara requested that the delivery be sped up.

The S-400 Triumf (NATO reporting name: SA-21 Growler) is an advanced long-range anti-aircraft missile system that went into service in 2007. It is designed to destroy aircraft, cruise and ballistic missiles, including medium-range ones, and can also be used against ground objectives. The S-400 complex can engage targets at a distance of 400 km and at an altitude of up to 30 km.