Turkey to move ahead with S-400 missile deal despite US pressure, said Russian Deputy PM
Turkey's relationship with the US and other NATO members is strained
Turkey has completed purchase of Russian S-400 missiles, says Defence Minister
Ankara is discussing a further deal with a European consortium to help it develop its own missile defence system, Defence Minister Nurettin Canikl said
NATO: Turkey will face consequences if it buys S-400 missiles
Their presence creates challenges for allied assets, NATO official said