According to Press TV quoting a Pentagon statement, Mattis made the request during a meeting with Turkish Defense Minister Nurettin Canikli on the sidelines of a NATO summit in Brussels on Wednesday, ahead of Secretary of State Rex Tillerson’s visit to Turkey.
“(Mattis) called for a renewed focus on the campaign to defeat Daesh, and to preventing any vestige of the terrorist organization from reconstituting in Syria,” the statement said, using an acronym for the terrorist group.
Tillerson is scheduled to arrive in Turkey on Thursday for a two-day visit.
Turkey last month launched a military incursion into Syria’s northwestern region of Afrin to counter Kurdish People’s Protection Units (YPG) militants.
NATO member Turkey last month launched “Operation Olive Branch,” a new air and ground operation targeting the Afrin region, to oust the Kurdish People’s Protection Units (YPG), which Ankara views as a terrorist organization and the Syrian branch of the outlawed Kurdistan Workers’ Party (PKK).
The Turkish Afrin operations are not authorized by Damascus.
However, the United States considers the YPG the most effective force fighting Daesh on the ground in Syria and has provided weapons, training and air support to the group.
On Tuesday, Turkish President Recep Tayyip Erdogan warned that Washington’s refusal to stop funding the Kurdish militants in Syria will affect Ankara’s decisions.
Addressing members of his ruling Justice and Development Party (AK Party) in parliament on Tuesday, Erdogan criticized Washington for supporting YPG militants.
“Our ally’s decision to give financial support to the YPG… will surely affect the decisions we will take,” Erdogan said.
The Turkish president had earlier said the YPG is trying to establish a “terror corridor” on Turkey’s southern border, linking Syria’s northern city of Afrin with a large Kurdish-controlled area to the east.
Senior authorities in Ankara have warned Washington that there could be a confrontation between Turkish and American troops in northern Syria if arms transfer to the Kurds was not stopped.