A handout picture taken and released on August 24, 2016 by the Turkey's President Press Service shows US Vice President Joe Biden (L) shaking hands with Turkish President Recep Tayyip Erdogan (R) at Turkish Presidential Complex in Ankara. US Vice President Joe Biden on August 24, 2016 said Washington had made clear that pro-Kurdish forces in Syria must not to cross west of the Euphrates River, a prospect alarming for Turkey. His comments come after Turkish troops launched an operation inside Syria to cleanse the key town of Jarabulus from Islamic State (IS) jihadists. / AFP PHOTO / TURKEY'S PRESIDENTIAL PRESS SERVICE / KAYHAN OZER / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / TURKEY'S PRESIDENTIAL PRESS SERVICE/ KAYHAN OZER- NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS KAYHAN OZER/AFP/Getty Images