The US State Department has expressed alarm over reports about possible tests by Turkey of its Russian-made S-400 missile systems.
"We are aware of these reports. We continue to object strenuously to Turkey's purchase of the S-400 air defence system, and are deeply concerned with reports that Turkey is continuing its efforts to bring the S-400 into operation. Our suspension of Turkey from the F-35 programme, in response to the S-400 acquisition, signalled the seriousness with which the administration approaches this issue”, a State Department spokesperson said on Tuesday.
They added that Washington continues to underscore "at the highest levels" that the S-400 deal between Ankara and Moscow "remains a major obstacle in the bilateral [Turkish-US] relationship and at NATO, as well as a risk for potential CAATSA [Countering America's Adversaries Through Sanctions Act] sanctions".
The spokesperson expressed hope that Turkish President Recep Tayyip Erdogan and those in his orbit will "understand" Washington's position on the issue.
The remarks came amid reports that Ankara had deployed its S-400 missile systems to the northern Turkish city of Samsun, probably for testing - something that has not been commented on by the country's authorities yet.
This followed the aviation blog Fighter Jets World citing unnamed intelligence sources as saying in mid-July that the Turkish military had started new field testing of the S-400s against the US-made F-16 and F-4 fighter jets at the Murted Air Base outside Ankara.
In November 2019, US Secretary of State Mike Pompeo voiced concern over Turkey testing the S-400 air defences, telling reporters that the US had "made very clear to the Turkish government" Washington's desire "to see them move away from putting into full operationalisation the S-400 weapons system".
US, Turkey at Loggerheads Over S-400
The deliveries of Russia's S-400s to Turkey began in July 2019, triggering a crisis in Ankara's relations with Washington.
Ankara defied the threats and continued negotiations with Russia on an extra batch of S-400s.
The US has repeatedly claimed that the Russian missile systems are incompatible with NATO security standards and may compromise the operations of its fifth-generation F-35 fighter jets, allegations that Turkey vehemently rejects.