ANKARA, September 23. /TASS/. Turkey has no intention to reverse its decision on the purchase and use of Russian S-400 anti-aircraft missile systems, Turkish President Recep Tayyip Erdogan told reporters aboard his plane returning from the United States on Thursday.

"I cannot say that the Turkish-American relations are living through a sound phase. Why? Listen, we purchased F-35s [US fifth-generation fighters] but they were not delivered to us. America should first deal with this situation instead of making excuses to us, referring to [the problem with their compatibility with] S-400s. Of course, we will do everything necessary, proceeding from international law. For us, the work with S-400s has been completed and we will not backtrack. The United States should understand this," the newspaper Sabah quoted Erdogan as saying.

Moscow and Ankara inked a deal in 2017 on the delivery of the Russian-made S-400 air defense system to Turkey, thereby making it the first NATO member state to purchase this air defense missile system from Russia.

Ankara’s decision to purchase the Russian-made system infuriated the United States and NATO. So far, Washington has not abandoned its efforts to make Turkey give up the Russian air defense system.

Turkey has not caved to US pressure and said that it would keep the S-400 system. Washington has responded by excluding Ankara from the US program of developing the fifth-generation F-35 fighter-bomber.

Turkish President Erdogan vowed in October last year that Ankara was not going to give up the S-400 system, despite Washington’s pressure.

S-400 ‘Triumf’

Russia’s S-400 ‘Triumf’ (NATO reporting name: SA-21 Growler) is the latest long-and medium-range surface-to-air missile system that went into service in 2007. It is designed to destroy aircraft, cruise and ballistic missiles, and can also be used against ground installations. The S-400 can engage targets at a distance of up to 400 km and at an altitude of up to 30 km under intensive enemy fire and jamming.