President Donald Trump speaks during a press conference in the Rose Garden of the White House in Washington, DC, on January 4, 2019 following a meeting with Congressional leaders on the government shutdown.

President Donald Trump threatened Turkey with devastating sanctions if America's NATO ally attacked Kurds following a U.S. troop withdrawal from Syria.

"Starting the long overdue pullout from Syria while hitting the little remaining ISIS territorial caliphate hard, and from many directions," Trump said on Twitter late Sunday. "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," the president added in another tweet.

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The White House, State Department and Pentagon did not respond to CNBC requests for comment or elaboration.

Turkish Foreign Minister Mevlut Cavusoglu responded, saying that nothing could be achieved with economic threats and that partner nations shouldn't communicate over social media, Reuters reported Monday. The minister added that Trump's Syria tweets stemmed from domestic politics.

American support for Kurdish militias in Syria has been a major thorn in relations between Washington and Ankara, as the latter views the Kurds as terrorists and a threat to their security.

The militias, known as the Kurdish People's Protection Units (YPG), are the armed wing of the Democratic Union Party (PYD), an offshoot of the designated terrorist group called the Kurdistan Workers' Party, which has carried out a decades-long insurgency against the Turkish state. They are also America's primary partners on the ground in Syria: The Pentagon has been supplying the YPG with weaponry, air support and training to battle IS since 2015, and the militias have suffered thousands of casualties fighting for the U.S.-led coalition.