"The purchase of S-400 anti-missile systems is Turkey's national interest, which does not have anything to do with the politics… The Russian air defense systems minimize Turkey's external dependence," Soylu was quoted as saying by the Anadolu news agency.
READ MORE: Turkey Rejects US Demand to Cancel Russian S-400 Deal — Reports
In December, Russia and Turkey signed a loan agreement for the supply of the S-400 air defense systems to Ankara. The deal triggered disagreements between Ankara and Washington, with the latter threatening to impose sanctions against Turkey, as the United States believes that the weapon is incompatible with the NATO defenses.
In late April, Turkish Foreign Minister Mevlut Cavusoglu said that Turkey was also considering purchasing US-made Patriot missile defense system or other air defense systems if it was able to get a fair offer from its NATO allies.