Turkish Prime Minister Binali Yildirim says the United States has made inconsistent statements about its plans to create a Kurdish-led Syrian border guard.
He also called on Washington to stand with Turkey against the emergence of such a force.
Turkey has reacted angrily to the US-led coalition’s stated plans to form a 30,000-strong Kurdish-led force, calling it an "army of terror" and vowing to crush it.
It has also said it will launch a military offensive against the enclave of Afrin and other Syrian Kurdish militia-controlled territories, and has been massing troops and tanks on its border.
US Secretary of State Rex Tillerson told reporters on Wednesday that the United States owes Turkey an explanation for saying that it is supporting the creation of a border security force in northern Syria.
Mr Tillerson said the "entire situation has been mis-portrayed, mis-described, and some people misspoke. We are not creating a border security force at all."
He said the US intended to provide training to local elements in areas liberated from the Islamic State group.
Turkish leaders were not satisfied. Mr Yildirim said Turkey had received consecutive "statements that contradict each other within the past three days".
"The US must eliminate the confusion and change its stance in favour of peace and improving relations with Turkey," he said during an address to police chiefs.
Asked about Mr Tillerson’s statement, Foreign Minister Mevlut Cavusoglu told Turkey’s CNN-Turk television in an interview that "we are not satisfied".
"Is our mistrust toward the United States continuing? Yes it is," he said, adding that Washington had not kept to its promise to take back weapons it had supplied to the Syrian Kurdish militia fighting the Islamic State group.
Turkey says the weapons frequently end up in the hands of outlawed Kurdish rebels fighting Turkey.
Turkey regards the Syrian Kurdish militia that controls Afrin and other areas along its border as an extension of the Kurdish insurgency and wants to prevent the establishment of a Kurdish corridor along the frontier.
The Kurdish militia, which forms the backbone of the US-backed Syrian Democratic Forces, now controls nearly 25% of Syrian territory. It is the US-led coalition’s chief ally in the campaign against IS militants in Syria.
Meanwhile, Turkey’s chief of military staff and the head of its intelligence agency travelled to Russia for talks expected to touch on the possible Turkish offensive in Afrin, where the Russian military is believed to have a presence.
A Turkish military statement said Gen Hulusi Akar and intelligence chief Hakan Fidan would meet with Russia’s military chief, Valery Gerasimov, to discuss regional security issues, the latest developments in Syria and ongoing peace efforts for the war-torn country.