MOSCOW/ANKARA President Tayyip Erdogan sought to build cooperation with Russian leader Vladimir Putin on Friday over military operations in Syria, as Turkey attempts to create a border "safe zone" free of Islamic State and the Kurdish YPG militia. Erdogan, referring to Islamic State's remaining stronghold, told a joint Moscow news conference with the Russian President "Of course, the real target now is Raqqa". Turkey is seeking a role for its military in the advance on Raqqa, but the United States is veering toward enlisting the Kurdish YPG militia - something contrary to Ankara's aim of banishing Kurdish fighters eastwards across the Euphrates river. Turkey considers the YPG the Syrian arm of the Kurdistan Workers Party (PKK) that has been fighting an insurrection on Turkish soil for 30 years. Washington, like Ankara, considers the PKK a terrorist group, but it backs the YPG. Russian-backed forces of Syrian President Bashar al-Assad are also operating in the north of the country, close to Turkish borders. Washington and Moscow are concerned fast-moving military developments could lead to serious clashes between Turkish forces and the YPG. "It should now be accepted that a terrorist organization cannot be defeated with another one," Erdogan said, referring to the enlistment of YPG by the United States to fight Islamic State. "As a country that has been battling terror for 35 years, terrorist organizations like Daesh (Islamic State), the YPG, Nusra front and others are organizations we face at all times.” TURKISH-KURDISH CLASHES INTENSIFY "We have kept all lines of communication open until now, and we will continue to do so from now on," Erdogan said. "Whether it is Turkey or Russia, we are working in full cooperation militarily in Syria. Our chiefs of staff, foreign ministers, and intelligence agencies cooperate intensely." The Turkish military said on Friday that 71 Kurdish militia fighters had been killed in Syria in the last week in what appeared to mark an escalation of clashes with the U.S.-backed YPG group vying for control of areas along Turkey's border. Including that 71, a total of 134 have been killed since Jan. 5. Syrian state media quoted a military source late on Thursday as saying Turkey's military had shelled Syrian government forces and their allies in northern Iraq, causing deaths and injuries. State-run SANA news agency quoted the military source as saying that the Turkish bombardment targeted Syrian border guard positions in the countryside near the northern city of Manbij. The area around Manbij has been controlled since last year by the Manbij Military Council, a local militia that is a part of the Syrian Democratic Forces (SDF), an umbrella organization of armed groups of which the YPG is also a part.