Anti-Daesh coalition to form border security force with US-backed SDF, which is controlled, manned by PKK/PYD terrorists.
The Foreign Ministry issued a statement saying Turkey had reiterated on numerous occasions that it was "wrong and objectionable" to cooperate with the PKK/PYD terrorist organization on the ground in Syria in order to fight Daesh and stabilize the areas liberated from it.
"On the other hand, the establishment of the so-called 'Syria Border Protection Force' was not consulted with Turkey, which is a member of the coalition," the statement said.
The Ministry added that it was also not known which coalition members approved this decision.
"To attribute such a unilateral step to the whole coalition is an extremely wrong move that could harm the fight against Daesh,” it said.
"Such initiatives, through cooperation with the PYD/YPG in contradiction with the U.S commitments and statements, endanger Turkey's national security and the territorial integrity of Syria, and are totally unacceptable," it said.
"We condemn insistence on this wrong approach and remind once again that Turkey is determined to and capable of eliminating any threats against the country," it added.
The coalition had issued a written statement to some media outlets earlier on Sunday, wherein it said that the coalition was working with the SDF to set up and train a Syria Border Protection Force.
Turkey has long protested U.S. support for the PKK/PYD, the Syrian offshoot of the PKK terrorist organisation, and its military wing PYG, while Washington sees it as a "reliable ally" in its fight against Daesh in Syria.
Listed as a terrorist organization by Turkey, the U.S. and the EU, the PKK has waged a terror campaign against Turkey for more than 30 years, leading to the deaths of more than 40,000 security forces and civilians -- including more than 1,200 since July 2015 alone, when it resumed its armed campaign against the Turkish state following a fragile cease-fire.