Turkish President Tayyip Recep Erdogan said he will discuss buying U.S. Patriot missiles with President Donald Trump this month, saying his personal bond with the U.S. leader could overcome a crisis caused by Ankara buying Russian air defense systems.

Turkey's purchase of the Russian S-400 missile system in July raised the prospect of U.S. sanctions, and the State Department has said an offer to sell Raytheon Co.'s Patriot missile defense system to Ankara has expired.

However, Erdogan told Reuters he had discussed buying Patriots in a phone call with Trump two weeks ago and would follow up when they meet at the United Nations General Assembly, which opens next week.

"I said no matter what package of ... S-400s we get, we can buy from you a certain amount of Patriots," Erdogan told Reuters. "But I said we have to see conditions that at least match up to the S-400s."

"He said: 'Are you serious?' I said: 'Yes,'" Erdogan said, adding that he told Trump they would discuss it in greater detail when they meet.

Asked whether he would also ask Trump to prevent the U.S. Treasury imposing a heavy fine on Turkey's state-owned Halkbank for violating U.S. sanctions on Iran, Erdogan said he was confident they could avoid such a "mistake," citing what he said was "a different kind of trust" between the two men.

"In my opinion a country like the USA will not want to hurt its ally Turkey any more. This is not a rational behavior," he said in an interview at the Ottoman Dolmabahce palace complex on the Bosphorus in Istanbul.