Turkey has issued the so-called NOTAM air space notice to restrict an area near its Black Sea coastal city of Sinop ahead of possible tests of the Russian-made S-400 missile system.
The NOTAM followed a NAVTEX maritime notice by Turkey restricting airspace off its Black Sea coast to allow S-400 tests, which NAVTEX said were due to be held between Friday and Saturday.
The NOTAM and NAVTEX notices come amid unconfirmed reports that an S-400 missile was fired into the sky on Turkey's Black Sea coast, where tests of the Russian-made air defences are due to take place.
Earlier, it was reported that Ankara had deployed the S-400 systems to its the Black Sea province of Samsun last week, with Turkish authorities making no official statements on the matter.
The US State Department responded by saying that they were deeply concerned over these reports and that Washington’s “suspension of Turkey from the F-35 programme, in response to the S-400 acquisition, signalled the seriousness with which the [US] administration approaches this issue”.
The State Department added 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 in NATO, as well as a risk for potential CAATSA [Countering America's Adversaries Through Sanctions Act] sanctions".
US, Turkey at Odds 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 the 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.
