Turkish President Recep Tayyip Erdogan announced - on Friday - that his country had tested the Russian S-400 air defense system, saying that Ankara did not heed Washington's objections to this step.

Erdogan told reporters, "The tests were conducted and are taking place. The US position does not concern us at all. If we do not test these capabilities that we have, what will we do?"

Turkey struck a deal with Russia to buy the S-400 system in 2017, and deliveries of the first 4 missile batteries - valued at $ 2.5 billion - began in July of last year.

Erdogan added that Turkey would continue to test military equipment, including light, medium and heavy weapons, many of which it had purchased from the United States.

"It seems that the gentlemen (in the United States) are particularly upset because this weapon is from Russia. We are determined and we will go on our path as we have always been ... we will not ask permission from the Americans," he said.

The Turkish president was surprised that Greece - which is also a member of NATO - possessed Russian S-300 missiles, without the United States being intercepted.

And local media said that the Turkish army had tested a missile from the S-400 system in the city of Sinop (north), and the news was not confirmed before Erdogan's speech today to reporters in Istanbul.

Erdogan pledged to test new types of advanced weapons (Anatolia)

The American position

Earlier, US State Department spokeswoman Morgan Ortagus said, "If this is confirmed, we will condemn in the strongest terms the S-400 missile test that is inconsistent with Turkey's responsibilities as a NATO ally and strategic partner of the United States."

She added, "The United States has clearly stated that it does not want to activate the S-400 system, and has clearly warned us of the potentially dire implications for our security relations in the event Turkey activates the system."

Turkey's purchase of the S-400 system in the context of its rapprochement with Moscow has caused disputes with several Western countries, which consider that the Russian system is not compatible with NATO equipment.

In response to the delivery of the first battery last year, the United States suspended Turkey's participation in the program to manufacture modern American warplanes, "F-35" (F-35), saying that the S-400 system could cause its technological secrets to be revealed.

Despite Washington's repeated threats, Erdogan confirmed several times that the system would be deployed.

Ankara defends its choice by saying that the United States refused to sell it the Patriot air defense system.