The intense Turkish airstrikes and shelling have killed and wounded hundreds of civilians and dozens of fighters since the operation started 14 days ago, it added.
The "Olive Branch" operation was launched on 20 January to capture the Afrin region and drive out the Kurdish YPG militia.
Five of the troops died when their tank was attacked near Afrin.
The Turkish army has used all its military capabilities and weapons, including the prohibited ones, but failed to advance into Afrin, the SDF said in a statement.
The Turkish army and allied Ankara-backed Syrian rebel forces are seeking to oust the YPG from its western border stronghold of Afrin but the operation so far has been marked by fierce clashes.
A previous statement said one serviceman was killed and another wounded in that attack.
Mevlut Cavusoglu and Nurettin Canikli called Sarp Ozer, who injured his hand and leg when PYD/PKK's rocket and mortar attack struck Hatay province, where he was covering Turkey's ongoing operation in Syria's Afrin region on Friday.
Ankara says that major progress has been made in the 15-day operation, with nearly 900 YPG fighters killed so far although it is not possible to verify these figures. "There is not much to go", he said. Turkey considers the YPG, the armed wing of the PYD, to be an extension of the Kurdistan Workers Party which has waged a decades-long insurgency in Turkey's mainly Kurdish southeast.