President Tayyip Erdogan said on Thursday he did not expect the United States to impose sanctions over Turkey’s planned purchase of a Russian missile defense system, but he would retaliate if it did, reports Reuters.

Speaking at a rare news conference for foreign media in Istanbul, Erdogan repeated that the purchase of Russian S-400 systems was a done deal and said the United States should think carefully before imposing sanctions on a NATO member.

“I do not see any possibility of these sanctions happening,” Erdogan said. However, if they did, “we will have sanctions of our own”.

Washington has repeatedly threatened to impose sanctions unless Ankara backs down from the S-400 purchase. Erdogan said the delivery of the system would start in the first half of July.