Turkish defence ministry says first S-400 parts delivered on Friday
The first shipment of Russian S-400 missile defence system parts arrived in Turkey on Friday, a development set to escalate tensions with the US which has warned of sanctions over the deal.
The S-400 consignment was delivered to the Murted Air Base outside the capital Ankara, according to the Turkish defence ministry in a statement.
"The delivery of parts belonging to the system will continue in the coming days," Turkey's Defence Industry Directorate said separately.
"Once the system is completely ready, it will begin to be used in a way determined by the relevant authorities."
The announcement triggered a weakening in the Turkish lira from 5.6775 against the dollar on Wednesday to 5.7.
President Erdogan said, after meeting President Donald Trump at a G20 summit last month, that the US did not plan to impose sanctions on Ankara for buying the S-400s.
Trump said Turkey, a NATO member country, had not been treated fairly yet did not rule out sanctions. But the US State Department issued another warning about the purchase this week.
"Turkey would face real and harmful consequences if it accepted the S-400s," US State Department spokeswoman Morgan Ortagus said on Tuesday.
Rejecting the warning, Turkey urged Washington on Wednesday not to take any measures that could "damage bilateral relations".
"We call on the US side not to take harmful measures that would discard diplomacy and dialogue and damage our relations," the Turkish Foreign Ministry said in a statement.
The US says the S-400s are not compatible with NATO's defence network and could compromise its Lockheed Martin F-35 stealth fighter jets, an aircraft Turkey is helping to build and planning to buy.
In addition, Washington believes that there is a risk that the Russian operators who will train the Turkish military in the S-400s may at the same time unlock the technological secrets of the new American stealth aircraft F-35 that Turkey also wants to acquire.
Under possible US sanctions, Turkey could face expulsion from the F-35 programme, a move Erdogan has dismissed. But Washington has already started the process of removing Turkey from the F-35 programme, halting training of Turkish pilots in the United States on the aircraft.
The officers behind the coup attempt in July 2016 to overthrow President Recep Tayyip Erdogan were based at Murted. Monday marks the third anniversary of the attempt.