Trump said that the U.S. will destroy Turkey if they harm Syrian Kurds, while Turkey, for its part, blamed the U.S. for being an unstable ally.
The United States President Donald Trump threatened Turkey with economic devastation if it attacks a U.S.-allied Kurdish militia in Syria, drawing a sharp rebuke from Ankara Monday and reviving fears of another downturn in relations between the NATO allies.
Relations between the United States and Turkey have long been strained by Washington's support for the Kurdish YPG, which Turkey views as an extension of the outlawed Kurdistan Workers Party (PKK) that wants freedom from Turkey.
Speaking in Riyadh, Secretary of State Mike Pompeo said he did not think the threat would change plans to withdraw troops from Syria. Asked what Trump meant by economic devastation, he said, "You'll have to ask the president."
"We have applied economic sanctions in many places, I assume he is speaking about those kinds of things, Pompeo said, adding he had not spoken with Ankara since Trump's comment.
Trump said Sunday the U.S. was starting the military pull-out from Syria that he announced in December but that it would continue to hit Islamic State fighters there.
"Will attack again from existing nearby base if it reforms. Will devastate Turkey economically if they hit Kurds. Create 20 mile safe zone...Likewise, do not want the Kurds to provoke Turkey," Trump wrote on Twitter.
Turkish presidential spokesman Ibrahim Kalin said Trump should respect Washington's alliance with Ankara.
"Mr @realDonaldTrump It is a fatal mistake to equate Syrian Kurds with the PKK, which is on the US terrorists list, and its Syria branch PYD/YPG," spokesman Ibrahim Kalin wrote on Twitter.
"Terrorists can't be your partners & allies. Turkey expects the US to honor our strategic partnership and doesn't want it to be shadowed by terrorist propaganda," he said Monday.
Trump announced last month he would withdraw U.S. forces from Syria, declaring they had succeeded in their mission to defeat the Islamic State group and were no longer needed.
However, U.S. officials have given mixed messages since then. The U.S.-led coalition said Friday it had started the pullout but officials said later it involved only equipment, not troops.
Turkish Foreign Minister Mevlut Cavusoglu said Ankara was not against the idea of a secure zone along the border but said strategic partners and allies should not communicate over social media.
"Nothing can be achieved by threatening Turkey economically. We need to look at how we can coordinate together and how we can solve this," he said in a news conference with Luxembourg's foreign minister.
A senior Turkish official told Al Jazeera that the U.S. has been "a highly unreliable partner" to Ankara.
"The problems and misunderstandings between the US and Turkey are results of the confusion and cacophony between the actors at different levels of the US administration and institutions," Yasin Aktay, advisor to President Recep Tayyip Erdogan in his AK Party, said Monday in an interview.
"As a NATO ally, the U.S. supports and prefers to cooperate with a threat to another NATO ally, emerging as a highly unreliable partner," he added.