As noted, the fourth aircraft with elements of air defense systems arrived in Ankara.
Earlier, the first components of the S-400 missiles were delivered to the military base in the province of Ankara.
Subsequently, a group of US senators called on US President Donald Trump to impose sanctions on Turkey in connection with the start of deliveries of Russian S-400.
Expert Edward Lozansky commented on the NSNS likelihood of imposing sanctions against third countries because of the C-400.