The SDF is largely made up of the YPG - the Syrian affiliate of the PKK terror group. But it still enjoys large huge US support.
The US says they're doing the best job of fighting Daesh in Syria.
The SDF have won a number of battles against Daesh and control large parts of northern Syria as a result.
But US support for the SDF has been fiercely opposed by Turkey.
For Ankara, the SDF is nothing more than a terrorist group.
The group is dominated by the YPG, the armed wing of the PKK terrorist group.
The PKK has waged an armed campaign against the Turkish state since 1984.
The group, which is listed as a terrorist organisation by Turkey, the US and the EU, has been responsible for killing over 40,000 civilians and security personnel.
TRT World's Yasin Eken reports.