"The US and Russian ambassadors were called to the ministry yesterday (Tuesday) to convey Turkey's views about the PYD (Democratic Unity Party)," the foreign ministry official told AFP. "Necessary warnings were issued."
Turkey labels the PYD as the Syrian offshoot of the outlawed Kurdistan Workers' Party (PKK) which has waged a bloody insurgency since 1984.
US-led coalition forces have parachuted in ammunition to anti-ISIL militants in northern Syria, stepping their backing for groups battling terrorists.
The move follows the Pentagon's announcement last week that it would halt its much-criticized program to train the so-called moderate groups fighting Syrian President Bashar al-Assad, and instead focus efforts on equipping pre-screened militant leaders from groups actively fighting ISIL.
Russia is intervening in Syria with bombing raids in support of the President Bashar al-Assad. A top Russian official last week allegedly held talks with PYD leader Salih Muslim to discuss the fight against ISIL.