Despite opposition from the US, the controversial delivery of Russian S-400 missiles to Turkey has begun. This was announced by the Ministry of Defense in Ankara. Where exactly the S-400 will eventually be stationed, is not known. President Recep Tayyip Erdogan had said that would be decided by the General Staff of the Armed Forces.

The US - also part of NATO - has threatened sanctions as soon as the S-400 batteries are taken over by the Turkish military. Among other things, the government in Washington fears that Russia will be able to obtain data on the capabilities of the new US stealth aircraft F-35 via the sensitive S-400 radars. Turkey is a partner in the construction of the F-35 and should get about 100 jets. The US is now threatening to throw Turkey out of the F-35 program, despite payments of more than $ 1 billion already made in late July.

US sanctions could hit Turkey hard. In the past year, such sanctions had severely damaged the Turkish economy and currency because of an American pastor detained in Turkey.

Turkey has been intensifying its attempts to dispel the concerns of the NATO partner for days. Foreign Minister Mevlüt Çavuşoğlu repeatedly said that the system is used only in an emergency. The Cumhuriyet newspaper said earlier that the S-400 would work with an independent radar and not network with other systems.

Other NATO members have so far held back with public criticism of the deal. Some fear that business and conflict with the US could lead to a further rapprochement between Turkey and Russia - thereby eroding the Alliance. The topic is treated as a bilateral matter. "All sides are very interested in the fact that the alliance is not damaged," quotes the news agency dpa a NATO diplomat. The Turkish channel Habertürk had reported that Russian technicians were already in the country from Monday on.