Turkish President Recep Tayyip Erdogan (R) and Russian President Vladimir Putin attend a joint press conference following their meeting in Ankara, Turkey, on Sept. 28, 2017. Turkish President Recep Tayyip Erdogan said on Thursday that both Turkey and Russia uphold the territorial integrity of Iraq and Syria. (Xinhua/Qin Yanyang)

Turkish President Recep Tayyip Erdogan speaks at a joint press conference with Russian President Vladimir Putin (not in the picture) in Ankara, Turkey, on Sept. 28, 2017. Turkish President Recep Tayyip Erdogan said on Thursday that both Turkey and Russia uphold the territorial integrity of Iraq and Syria. (Xinhua/Qin Yanyang)

Russian President Vladimir Putin speaks at a joint press conference with Turkish President Recep Tayyip Erdogan (not in the picture) in Ankara, Turkey, on Sept. 28, 2017. Turkish President Recep Tayyip Erdogan said on Thursday that both Turkey and Russia uphold the territorial integrity of Iraq and Syria. (Xinhua/Qin Yanyang)