TURKISH president Recep Tayyip Erdogan has called on Nato to take a stand against the US over its plans to form a 30,000-strong Kurdish-led border security force in Syria.

Turkey has threatened to launch a military offensive against Syrian Kurdish militias, which Ankara considers to be terrorists.

Erdogan has accused fellow Nato ally the US of creating an “army of terror” in Syria along the border with Turkey, and vowed to crush the force.

Addressing his ruling party’s deputies, 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.”

Erdogan said Turkey’s military chief would discuss the issue in Brussels.

Ties between Turkey and the US have deteriorated over American support for the Kurdish militia, known as the People’s Defence Units, or YPG, which Turkey says is a major threat to its security. The US has relied on the YPG as the backbone of a Syrian force that drove Daesh from much of northern and eastern Syria with the help of US-led airstrikes.

The coalition said the new force, expected to number as much as 30,000 in the next few years, is a key element of its strategy in Syria to prevent the resurgence of Daesh there.

Erdogan reiterated that Turkey plans an imminent intervention in the Kurdish-controlled enclave of Afrin in northern Syria.

Turkey has sent reinforcements to its border in recent weeks and Erdogan said this week that Turkish troops were already firing artillery at Afrin from the border.

Speaking after his speech to party legislators, Erdogan said Turkey would conduct the operation in Afrin with Turkish-backed Syrian opposition forces.

Asked whether he planned to discuss the Kurdish-led border force with US president Donald Trump, Erdogan said he had no plans to call the US leader.

The Turkish leader was quoted as saying: “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.”