Turkey on Friday received the first batch of Russia's S-400 missile defense system, sparking NATO "concern" and risking deepening tensions with the United States, AFP reports.
The delivery of the system to an air base in the Turkish capital Ankara comes after Washington warned this week that there would be "real and negative" consequences if Turkey bought the defense system.
NATO, which counts Turkey as one of its members, is "concerned about the potential consequences" of the purchase, an official told AFP.
Turkey and the United States have long been at odds over Ankara's decision to purchase the S-400s.
Washington says the S-400 poses a threat to the Lockheed Martin Corp F-35 stealthy fighters, which Turkey also plans to buy.
The US also believes the S-400 sale is part of Russian efforts to disrupt the alliance amid Western concern over Erdogan's burgeoning relationship with Putin.
Turkish officials insist that the deal to purchase the S-400 does not affect the security of the US and have repeatedly stressed that they will go ahead with the deal despite Washington’s objections.
Turkish President Recep Tayyip Erdogan has said he is confident Turkey will not face US sanctions. The Turkish leader recently he said he would use his "good" relationship with US President Donald Trump to try to defuse the crisis over the S-400 purchase.
On Friday, the Turkish defense ministry issued a statement confirming "the delivery of the first shipment of parts of the S-400 long range regional air missile defense system" had begun.
It was not immediately known where the system would be deployed or when it would be operational.
Turkey's Presidency of Defense Industries said in a statement that the delivery of the system's other parts would continue "in the coming days".
Kremlin spokesman Dmitry Peskov told journalists on Friday that "everything is happening in strict accordance with the agreements and signed contracts, all obligations are being carried out."
US officials said recently that the United States has decided to stop accepting any additional Turkish pilots who planned to come to the United States to train on F-35 fighter jets due to the S-400 purchase.
The US State Department has said Turkish officials are fully aware of legislation -- the Countering America's Adversaries Through Sanctions Act -- which mandates sanctions for any "significant" purchases of weapons from Russia.
Washington has given Ankara until July 31 to cancel the S-400 purchase or have its pilots kicked off its F-35 training course and expelled from the US.
(Arutz Sheva’s North American desk is keeping you updated until the start of Shabbat in New York. The time posted automatically on all Arutz Sheva articles, however, is Israeli time.)