BRUSSELS – The U.S. envoy to NATO said Tuesday that Turkey will be axed from the high-tech F-35 fighter jet program if it goes ahead with plans to buy Russian S-400 air defense missiles.

U.S. Ambassador Kay Bailey Hutchison said “there will be a disassociation with the F-35” if NATO member Turkey buys the Russian missile system, as President Recep Tayyip Erdogan has vowed to do.

Speaking on the eve of NATO talks in Brussels, Hutchison said “we cannot have the F-35 in any way affected by, or destabilized by, having this Russian system.”

The United States and other NATO allies have repeatedly complained about the purchase, saying the S-400 is not compatible with other allied systems and represents a security threat, particularly to the F-35.

But Hutchison said Turkey does not appear ready “to retract on the sale.”

Indeed, Erdogan repeated Tuesday that Turkey had no intention of doing so.

“Turkey does not negotiate, seek permission or bow to pressure from other countries on the issue of meeting its security needs,” the Turkish leader told his ruling party’s legislators.

“The S-400 issue is directly related to our sovereign rights, and we will not step back (from this decision),” he said.

Erdogan also reiterated that Turkey was expected to take delivery of the Russian system next month.