Addressing a press conference following the first session of Istanbul Program of Action for Least-Developed Countries in Turkey's Mediterranean resort province of Antalya Friday, Cavusoglu termed the act as an unacceptable move.

"Wearing an insignia of a terrorist organization by U.S. soldiers, who are our ally and are assertive about fighting against terrorism, is unacceptable," he said.

"Our suggestion to them is that they should also wear Daesh, al-Nusra and Al-Qaeda insignias during their operations in other regions of Syria. They can also wear the Boko Haram insignia when they go to Africa," he added.

Cavusoglu’s remarks come after photographs of U.S. troops sporting YPG’s insignia’s on their uniforms went viral online.

The pictures show the soldiers near the frontlines of a Syrian Democratic Forces (SDF)-led offensive on Daesh's Syrian stronghold, Raqqa. At least one photo was allegedly taken at al-Fatisah, a small village 25 kilometers (16 miles) from the city.

The SDF primarily consists of terrorists from the YPG, the armed wing of the PYD, which is considered by Turkey as the Syrian affiliate of the PKK terror group.

It also includes a host of Arab, Christian and other fighters.

Turkey designates both the PYD and YPG as terrorist groups, while Washington continues to support the YPG as its "effective partner" in the fight against Daesh.

The U.S. often also provides air cover to the group and U.S. troops have been sent on an advise-and-assist mission to help the YPG fight Daesh.

Recalling the remarks of U.S. President Barack Obama and U.S. Secretary of State John Kerry to Turkish President Recep Tayyip Erdogan on the YPG and PYD terror groups, Cavusoglu said they told us that the YPG and PYD were not to be trusted and that the U.S. was on Turkey's side in the fight against terrorism.

"[But now] they are wearing the insignia of a terrorist organization, which is responsible for the last two terror attacks in Ankara," Cavusoglu said.

Two separate bomb attacks in Ankara on Feb.17 and March 13 had left dozens of people dead and scores others injured.

Anadolu Agency