Turkey's president has called on Nato to take a stance against the US, a fellow ally, over its plans to form a 30,000-strong Kurdish-led border security force in Syria.
Turkey has been threatening to launch a new military offensive in Syria against Syrian Kurdish militias, which Ankara considers to be terrorists because of their affiliation with a outlawed group fighting an insurgency in southern Turkey.
On Monday President Recep Tayyip Erdogan accused Washington of creating an "army of terror" in Syria, along the border with Turkey, and vowed to crush the US-backed border force.
Addressing his ruling party's deputies on Tuesday, Mr Erdogan questioned Nato's stance on the issue, saying: "Hey Nato! You are obliged to make a stance against those who harass and violate the borders of your members."
Ties between Turkey and the US have deteriorated over the latter's support of the Kurdish militia, known as the People's Defense Units, or YPG, which Turkey says is a major threat to its security.
The US however has relied on the YPG - the backbone of a Syrian force that drove Islamic State of Iraq and the Levant (Isil) from much of northern and eastern Syria with the help of US-led airstrikes.
The coalition has said the new force, expected to reach 30,000 in the next several years, is a key element of its strategy in Syria to prevent the resurgence of Isil.
Mr Erdogan on Tuesday reiterated that Turkey planned an imminent intervention in the Kurdish-controlled enclave of Afrin in northern Syria. Turkey has sent reinforcements to its border in recent weeks and Mr Erdogan said this week that Turkish troops were already firing artillery at Afrin from the border.
Overnight on Monday, heavy shelling was reported in Afrin and the YPG reported the death of one of its fighters.
Asked whether he planned to discuss the Kurdish-led border force with President Donald Trump, Mr Erdogan said he had no plans to call the US leader.
"We discussed the issue before. He said he would get back to me. I won't call him as long as he does not get back to me," Anadolu quoted Mr Erdogan as saying.