ANKARA, November 23. /TASS/. Russian-made S-400 surface-to-air missile systems will operate autonomously in Turkey, Turkish Defense Minister Hulusi Akar said in an interview with the Qatari Al Jazeera TV Channel cited by the Anadolu news agency on Saturday.

"The Russian systems will assume combat duty in the stand alone system mode. We have stated from the very beginning that the S-400s will operate autonomously," the Turkish defense chief said.

The head of the Turkish Defense Ministry stressed that "S-400s are a very important mechanism for ensuring Turkey’s defense and security."

The Turkish defense minister again warned Western partners that Ankara "reserves the right to study alternative options," if the US refuses to hand over fifth-generation F-35 fighters to Turkey.

"Of course, we will be forced to look for other options. All the sides should understand this," Akar added.

Turkish President Recep Tayyip Erdogan said on November 19 he told US President Donald Trump that Ankara would not give up the Russian-made S-400 systems.

Russia announced in September 2017 that it had signed a $2.5 billion deal with Turkey on the delivery of S-400 anti-aircraft missile systems to Ankara. Under the contract, Ankara will get a regiment set of S-400 air defense missile systems (two battalions). The deal also envisages partial transfer of production technology to the Turkish side.

Turkey is the first NATO member state to purchase such air-defense missile systems from Russia. The deliveries of S-400 air defense systems to Turkey began on July 12, 2019.

The United States and NATO have been making attempts to prevent Turkey from purchasing Russia's S-400 missile systems. Washington has warned on many occasions that it may impose sanctions on Turkey, if Ankara presses ahead with the S-400 deal. On July 17, the press secretary of the US White House said in a written statement that Turkey’s decision to acquire Russian-made S-400 air defense missile systems rendered Ankara’s further participation in the US F-35 program impossible.

The S-400 ‘Triumf’ is the most advanced long-range air defense missile system that went into service in Russia in 2007. It is designed to destroy aircraft, cruise and ballistic missiles, including medium-range missiles, and can also be used against ground installations. The S-400 can engage targets at a distance of 400 km and at an altitude of up to 30 km.