President Recep Tayyip Erdogan on Saturday demanded an apology from U.S. Vice President Joe Biden and warned he would become "history for me" over comments in which he said the Turkish leader had admitted that Turkey had made mistakes by allowing foreign fighters to cross into Syria.
Erdogan denied ever saying that and told reporters in Istanbul that Biden "will be history for me if he has indeed used such expressions."
Responding to questions following his speech at the Harvard Kennedy School on Thursday, Biden described Erdogan as "an old friend." Biden added: "He (Erdogan) said: 'You were right. We let too many people through.' Now they're trying to seal their border."
Erdogan said: "I have never said to him that we had made a mistake, never. If he did say this at Harvard then he has to apologize to us."
The spat comes as Turkey, a NATO ally, is expected to define the role it will play in the U.S.-led coalition against the Islamic state militants who have captured a swath of Iraq and Syria, in some cases right up to the Turkish border.