Turkish President Recep Tayyip Erdogan speaks to the media during a press conference in Ankara, Turkey, in this Thursday, March 12, 2015, file photo. (AP Photo/Burhan Ozbilici, file)
Marines hold umbrellas as President Barack Obama and Turkish Prime Minister Recep Tayyip Erdogan participate in a joint news conference in the Rose Garden of the White House in Washington, Thursday, May 16, 2013. (AP Photo/Charles Dharapak)
Turkish President Recep Tayyip Erdogan listens to Pope Francis during a meeting at the Presidential palace in Ankara, Turkey, Friday, Nov. 28, 2014. (AP Photo/Burhan Ozbilici) ** FILE **
Turkish President Recep Tayyip Erdogan has been under international criticism for preventing heavy weapons or forces to use his territory to help Kurds in Kobani. Allowing peshmerga fighters to cross into Syria appears to be the product of a compromise, a former Turkish diplomat says.
** FILE ** Turkish Prime Minister Recep Tayyip Erdogan addresses his supporters at parliament in Ankara, Turkey, Tuesday, July 22, 2014. (AP Photo/Burhan Ozbilici)
** FILE ** Turkey's Prime Minister Recep Tayyip Erdogan addresses members of his ruling party in parliament in Ankara, Turkey, Tuesday, May 27, 2014. (AP Photo/Burhan Ozbilici)