AP Photo
Greece's President Prokopis Pavlopoulos, right, delivers a speech as Turkey's President Recep Tayyip Erdogan, left, listens during an official dinner in Athens, Thursday, Dec. 7, 2017. The presidents engaged in a thinly-veiled verbal spat over the treaty and the Muslim minority in northeastern Greece, when they met earlier in the day, a tense start for the first official visit by a Turkish president to Greece in six decades. (AP Photo/Thanassis Stavrakis)