ankara president tayyip erdogan say friday turkey need clear afrin region northwest syria kurdish ypg militia fighters forefront battle islamic state insurgents erdogan speak ankara officials rule ak party also express disappointment unite state back ypg ankara view ypg extension outlaw kurdistan workers party pkk fight decades-long insurgency turkey designate terrorist group turkey unite state european union need cleanse afrin structure call ypg terrorist organization erdogan say turkey long anger unite state support ypg erdogan repeatedly accuse washington violate alliance two countries greatly disappoint unite state keep promise many issue could resolve easily ... push dead-end say turkey express displeasure u.s. stance toward deal ypg islamic state hundreds militants withdraw syrian city raqqa fell syrian democratic force erdogan previously say afrin would ankara agenda current operation syria idlib province turkey russia set observation point de-escalation deal agree ankara moscow tehran ease bloodshed six-year-old syrian conflict erdogan say considerable progress make turkey military operation idlib due co-operation three power russia iran back syrian president bashar al-assad turkey support rebel oppose share common foe islamic state erdogan say turkey must clear syria 's afrin ypg militia