Reuters cited a senior member of the Syrian Democratic Forces backed by the US as saying that the group had killed tens of Turkish forces and allied FSA rebels since the start of the "Olive Branch" operation, however, failing to provide an exact figure.
According to SDF official Redur Xeli, the Turkish army is greatly exaggerating the number of the YPG and SDF fighters eliminated in its military campaign.
"The whole world knows Daesh is not present in Afrin," Redur Xelil told the news agency.
Turkish and Syrian Kurdish officials and media have provided competing claims over the state of the operation so far, although at least two Turkish soldiers, and several dozen FSA and SDF troops have been killed, according to various reports.
On Monday, the Kurdish-led SDF announced that they are considering sending reinforcements to Afrin amid the Turkish operation there.
After the Turkish General Staff announced on Saturday the launch of the operation in Afrin against the PKK and the YPG on Saturday, the SDF expressed readiness to "defend ourselves and our people." The campaign, which started with airstrikes to support the Free Syrian Army rebels, has been followed by a ground operation by the Turkish military on Sunday.
Most recently, the Pentagon chief, James Mattis, accused Ankara's ongoing military campaign in the Kurdish enclave of Afrin of hampering what he said was the fight against terrorism. Earlier, US State Secretary Rex Tillerson saying that Washington has been "engaged" with Ankara and asked "both sides" to show restraint, please minimize the impact on civilian casualties.
Ankara has been mulling an operation in Afrin since the US announced plans to build a 30,000-strong Kurdish-led Syrian Democratic Forces (SDF) security force on Syria's border with Turkey, which President Recep Tayyip Erdogan called a "terrorist army." The force was expected to consist to a great extent of People's Protection Units (YPG) militia, which Turkey classifies as a terrorist group affiliated with its own illegal Kurdish organization, the Kurdistan Workers' Party (PKK), which calls for Turkish Kurds' autonomy from Ankara.