AZAZ, Syria / ANKARA, Turkey

The U.S. is taking measures against a possible counter-terror operation led by Turkey in Syria's northern Manbij district. 

The U.S. has deployed military reinforcements to Manbij, west of Euphrates River, according to information Anadolu Agency received from trustworthy local sources in Manbij.

Approximately 300 U.S. soldiers arrived in Manbij in a convoy which included many armored vehicles and construction machines.

The reinforcements were deployed near the Sajur River, which forms the frontline between Euphrates Shield area and YPG/PKK invaded area. 

Also, reinforcements were deployed around Zub'ul Bayn village, west of Manbij.

The additional forces are now patrolling Sajur River shore daily. Previously, the patrols occurred weekly.

The U.S. forces are also patrolling Ras al-Ayn area, opposite Turkey's Ceylanpinar border gate, since the last three days.

Manbij district was invaded by YPG/PKK terror group in Aug. 2016 with U.S. support. 

Turkey launched Operation Olive Branch on Jan. 20 to clear terrorist groups from Afrin, northwestern Syria, amid growing threats from the region.

On March 18, Turkish-backed troops liberated the town of Afrin, a major hideout for the terrorist organization PYD/PKK since 2012.  

Ankara said it might also extend its operation further east to Manbij unless the PYD/PKK terrorist group leaves the strategically located city.

However, U.S. military support for the terrorist PYD/PKK group in Manbij has strained ties between Ankara and Washington and has led to fears of potential clashes on the ground between troops of the two NATO allies, since there are roughly 2,000 U.S. troops in the city.

Turkey and the U.S. have established working groups to discuss the stabilization of Manbij and to prevent any undesirable clashes.

But due to the abrupt departure of former U.S. Secretary of State Rex Tillerson, who helped establish the working groups, the future of Manbij remains unknown. 

The U.S. has supported the YPG/PKK under the name of SDF, which is considered by Ankara as the Syrian offshoot of the PKK terror organization that has waged a more than 30-year war against the Turkish state.