Erdogan denied ever saying that and told reporters today that Biden "will be history for me if he has indeed used such expressions."
Biden told an audience during a speech at the Harvard Kennedy School on Thursday: "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 apologise to us.