By Michael Hernandez

WASHINGTON

The U.S.-backed Syrian Democratic Forces (SDF) and the Syrian Arab Coalition (SAC) have taken the pivotal city of Tabqa and the dam there from Daesh terror group, U.S. Central Command said Thursday.

The forces had ousted Daesh militants from a nearby airfield in late March, and had been working to upend the group's control of the area for over a month.

Central Command said Daesh accepted the SDF's terms of defeat, and the coalition "tracked fleeing fighters and targeted those that could be safely hit without harming civilians".

Daesh's defeat in Tabqa marks a major milestone for the coalition's effort to encircle Daesh's de facto Syrian capital, Raqqah, ahead of a planned attack on the city.

The victory closely follows the U.S. announcement that it would begin to directly arm "Kurdish elements" of the Syrian Democratic Forces (SDF).

SDF ranks include the YPG, an organization Ankara considers the Syrian affiliate of the PKK, which is listed as a terrorist organization in Turkey, the U.S., and EU.

Washington has relied heavily on the YPG in its campaign against Daesh but until recently had not directly armed the group as a matter of policy.

The recent shift has angered the Turkish government, which views the change as a threat to its security.

Prime Minister Binali Yildirim said Wednesday, "You cannot destroy a terrorist organization using another terrorist organization."

After meeting with Yildirim in London, Defense Secretary James Mattis said he has "no doubt" that Turkey and the U.S. "will work this out with due consideration, significant attention paid to Turkey's security, to NATO's security, and the continuing campaign against" Daesh.

"We agree 100 percent with Turkey's concern about PKK, a named terrorist group," he told reporters en route to Washington. "It is conducting an active insurgency in Turkey. It has orchestrated the killing of innocent Turkish civilians and Turkish soldiers. And we support Turkey in its fight against PKK as a fellow NATO member, just like all the NATO countries stand with Turkey against the PKK."

The PKK resumed a 30-year armed campaign against the Turkish state in July 2015.

Since then, PKK terrorist attacks have lead to the deaths of more than 600 security personnel and claimed the lives of numerous civilians, including women and children.

Meanwhile, more than 7,000 PKK terrorists have since been killed in army operations.