Turkish Chief of General Staff General Hulusi Akar said on Tuesday that Turkey "would not and will not allow" arming the Kurdish terrorist group YPG in Syria, news agencies reported.
Speaking at a NATO meeting in Brussels, Akar said that "it is unacceptable to support the [Syrian Kurdish People's Protection Units] (YPG) under the guise of being an 'operational partner.'"
He stressed that the YPG is an extension of the PKK and called for the US to "return from its mistake" in supporting the YPG-led Syrian Democratic Forces (SDF).
Several top Turkish officials have announced their anger with the US plan to form a border security forces in the north of Syria in cooperation with the YPG.
On Monday, the Turkish President Recep Tayyip Erdogan said that his country is ready "at any moment" to start an operation in the besieged border area of Syria.
He described the forces formed by the US as a "an army of terrorists created by the US on the Turkish borders," vowing to destroy it.
Read: US-led coalition helps build new Syrian force, angering Turkey
Speaking at a Justice and Development (AK) Party parliamentary group meeting in Ankara, he said: "NATO, you are obliged to take a stand against those who harass the borders of one of your partners." Then, he asked: "To date, what position have you adopted?"
He also said that the Turkish army would conduct its operations in the north of Syria with the assistance of the Syrian opposition.
"This fight is made for them. We are helping our brothers there so that they can protect their own territories," said Erdogan, stressing that the Turkish army would "destroy" all terror spots in Syria one by one, starting with the Afrin and Manbij regions.
Last Thursday, the Turkish foreign minister told his American counterpart that keeping FETO's leader in the US and arming YPG would negatively affect mutual relations between the two countries.