ATHENS – Turkey's purchase and testing of the Russian-made S-400 missile defense system has so irked the United States that six F-35 fighter jets that were going to be sold to Turkey will go to Greece instead.

That comes during increasingly tense times as Turkey has gone ahead with plans to hunt for oil and gas off Greek islands, with warships from the two countries shadowing each other near Kastellorizo amid fears of a conflict.

The Russian system could compromise the defense of NATO, to which Greece, Turkey and the US belong and was purchased from an ideological enemy of the group, Turkish President Recep Tayyip Erdogan ignoring criticism. 

Citing Greek media, the news site i24 News said Greece will be sold the jets instead, boosting its Air Force that has engaged in regular mock dogfights with Turkish jets frequently violating Greece's airspace.

A recent visit of US State Secretary Mike Pompeo to Greece concluded with the decision to sell 20 fighter jets to Athens, with the first six arriving in 2022, Hebrew-language outlet Maariv reported.

The US and Greece are expected to renew a defense agreement before it is due to soon expire, seen extending the deal until 2025. The US Navy has a base on Souda Bay on Crete.

The US US Department of Defense condemned “in the strongest terms Turkey’s October 16 test of the S-400 air defense system. “We are opposed to Turkey testing this system, it could have serious consequences for our defense relations,” it added.

Greece has been beefing up its arsenal with arms and ammunition and equipment and is going to buy Rafale fighter jets from France, which has aligned itself with Greece against Turkish provocations.