Turkish President Recep Tayyip Erdogan has said it would be robbery for the United States to deny Turkey the F-35 fighter jets it has bought.
He said Turkey had so far paid 1.4 billion for the F-35s and that four jets out of 116 had been handed over.
Meanwhile, US government said that the administration intends to pull Turkey from the F-35 fighter jet programme if it takes delivery of the Russian S-400 system.