Turkey will activate as planned the S-400 missile defense systems acquired from Russian Federation, once the relevant military personnel complete their training, the Turkish Defense Minister Hulusi Akar said on November 21.
Turkey, however, says that the S-400 would neither be integrated into North Atlantic Treaty Organisation systems, nor pose a threat to the alliance.
The US argues there is a risk that sensitive technological information could be leaked if it is used alongside Western equipment such as the new F-35 jet. Turkey has crossed "another red line" by starting tests of the radar detection system it purchased from Russian Federation as part of the S-400 missile defense system, US Senator for Maryland Christopher Van Hollen said.
Turkey took delivery of two Russian S-400 batteries this year, dismissing warnings from the United States that they pose a threat to North Atlantic Treaty Organisation security.
The Milliyet newspaper, which has close links to the government, said Monday that the military is planning to test the S-400s that are now deployed at an airbase on the outskirts of Ankara.
Ankara began receiving the first batch of S-400s in July but they are not yet operational, though Turkish media reported on Monday that Turkish F-16 warplanes would fly over the country's capital to test the system.
So far, the United States has appeared reluctant to impose threatened sanctions on Turkey over the purchase, with officials saying it could be spared if it does not activate the S-400 system - though this option has been rejected by Turkey.
Dealers said the reports had a negative impact on the lira, which weakened to 5.7380 against the dollar from a close of 5.7140 on Friday. Those comments came after President Tayyip Erdogan met US President Donald Trump at the White House.
During the meeting, Trump reportedly said Ankara needed to drop the S-400 system and that in return, US was ready to sell Ankara US Patriot systems.
In a speech in February, U.S. Vice President Mike Pence declared that the Trump administration has "made it clear that we will not stand idly by while North Atlantic Treaty Organisation allies purchase weapons from our adversaries". Washington warned on many occasions that it may impose sanctions on Turkey, if Ankara presses ahead with the S-400 deal.