ISTANBUL (AP) — Turkey's president has criticized the United States, Russia and Iran for their presence in Syria and said their unwillingness to depose Syrian President Bashar Assad was contributing to Syrians' pain.

Recep Tayyip Erdogan was addressing a rally on Sunday marking the 563rd anniversary of the Ottoman conquest of Constantinople — present-day Istanbul.

Erdogan said: "What business have Russia and Iran (in Syria)? What business do the U.S. soldiers dressed up with the so-called patches of a terror organization have there?"

He was referring to images that surfaced this week showing American troops wearing the insignia of Syrian militia which Turkey considers to be a terror organization because of its links to Turkey's outlawed Kurdish rebels.

U.S. officials said the soldiers weren't authorized to wear the patches.