U.S. Secretary of State Rex Tillerson said on Thursday there was more discussion to be had on the way forward in Syria but that the status of President Bashar al-Assad would be decided by the Syrian people.

Speaking in the Turkish capital Ankara after talks with Turkey’s leaders, Tillerson also said there was “no space” between Turkey and the United States in their determination to defeat ISIS (the Islamic State in Iraq and Syria). 

He was responding to a question about U.S. support for the Kurdish YPG militia in Syria, which NATO ally Turkey sees as a hostile force.

Turkish President Tayyip Erdogan and his government have been incensed by U.S. support for the Syrian Kurdish YPG militia, seen by the Pentagon as a reliable partner but by Turkey as a hostile force with deep links to Kurdish PKK militants who have waged a three-decade insurgency against the Turkish state.

“What we discussed today are options that are available to us. They are difficult options. Let me be very frank, it’s not easy, they are difficult choices that have to be made,” Tillerson told a joint news conference with Turkish Foreign Minister Mevlut Cavusoglu.

Cavusoglu said the U.S. government accepted that there was no difference between the YPG militia and the PKK.

Tillerson condemned recent PKK attacks in Turkey but made no such acknowledgement. He said his talks in Ankara had focused on the creation of “stabilization zones” in Syria so refugees could return home and that a number of options on how to secure such areas were being explored.

Turkey, sheltering more than two million Syrians, has long called for such safe areas but the idea has gained little traction among Western allies who question how such zones can be carved out without a significant foreign military presence.