Turkey claims US forces in Syria are intentionally stalling the fight against the "Islamic State" to justify cooperation with Kurdish fighters. US Secretary of State Rex Tillerson is due in Ankara later this week.
Turkish Foreign Minister Mevlut Cavusoglu on Monday warned that Turkey-US ties were at a "critical point" and Washington needed to take "concrete steps" to regain Ankara's trust.
"Our relations are at a very critical stage," Cavusoglu said in televised comments in Istanbul. "Either we will improve ties or these ties will totally break down."