Washington says the S-400s pose a threat to the capabilities of its F-35 stealth fighter jets and has removed Turkey from the jet programme where it was a manufacturer and buyer.
Ankara says the S-400s will not be integrated into NATO and has called for a joint working group to discuss U.S. concerns. Kurtulmus repeated that Turkey would not bow to pressure to return the Russian systems, or leave them unused.
"Sorry, but we didn't procure these to hide them. We got them to meet Turkey's security needs," he said.