ANKARA, Turkey -- Turkey is willing to purchase U.S.-made Patriot air defense systems but will not agree to disposing of the Russian S-400 system it has already bought, Turkish President Recep Tayyip Erdogan said Thursday.
Speaking to reporters on board his plane on his way back from a meeting with Donald Trump in Washington, Erdogan said the U.S. president is engaged in "sincere efforts" to resolve disputes between the NATO allies.
Turkey took delivery of the Russian S-400 system this year, dismissing warnings from the United States that it poses a threat to NATO security.
As a result, Washington suspended Turkish participation in the multinational F-35 fighter jet program.
"We told them we can purchase the Patriots too. We regard the proposal to completely remove the S-400s [from Turkey] as meddling in our sovereign rights," the state-run Anadolu Agency quoted Erdogan as saying. "There can be no question of us leaving the S-400s and turning toward the Patriots."
Erdogan said: "I want both America and Russia to be my friend. All our efforts are geared toward that."
The dispute over the competing air defense systems is one component of the tension between the two countries. Turkey has also come under fire in Washington for its incursion into Syria last month to drive away Syrian Kurdish forces that fought with the U.S. against the Islamic State.
Turkey, meanwhile, is angry at the U.S. for supporting the Kurdish forces it views as a threat and for refusing to extradite a Muslim cleric it accuses of fomenting a 2016 coup attempt against Erdogan.
Erdogan also told reporters that he had returned a letter that Trump sent Oct. 9, urging Erdogan restraint over his plans for an offensive in Syria. Trump wrote: "Don't be a tough guy. Don't be a fool!"
Opposition parties had decried the letter as an insult to Turkey, calling on Erdogan to send it back to Trump.
Erdogan said Trump did not react when he handed him back the letter.