Washington has given Ankara an ultimatum as regards the latter's decision to buy Russian S-400 surface-to-air missiles worth 2.5 billion dollars, according to Turkish newspaper Hurriyet.
If Ankara proceeds with the sale, it will not receive 5th generation F-35 stealth fighters from the US, according to the Turkish newspaper.
The same report refers to a new deal between Turkey and the USA for the purchase of Patriot anti-aircraft systems with Turkish Foreign Ministry spokesman Hami Aksoy being quoted as saying that "discussions" about the Patriot systems were continuing.
The report adds that Turkey is considering the purchase of air defense systems form the French-Italian consortium Eurosam.
The ministry spokesman admits that the system being purchased from Russia is not compatible with NATO systems but that Turkey's goal is to develop a system that is compatible with NATO.