US military officials have arrived in Ankara for meetings aimed at preventing Turkey from carrying out an offensive against Washington’s Kurdish allies in northern Syria.

The high-level meetings have been characterised by US officials as a last ditch effort to dissuade Turkey from launching a unilateral attack, which the Trump administration has warned will harm the fight against Isis.

Turkey is pushing to establish a “safe zone” inside Syria that would be empty of fighters belonging to the Kurdish-led Syrian Democratic Forces (SDF), which it considers a terror group.

On Sunday, Turkish president Recep Tayyip Erdogan repeated a threat to cross into Syria without the approval of the US if Turkey’s conditions for a safe zone are not implemented.

“We entered Afrin, Jarablus, and Al-Bab. Now we will enter the east of the Euphrates,” Mr Erdogan said on Sunday, referring to previous incursions into Syria. “We can only be patient for so long.”

The US and Turkey have been at odds for months over the conditions for the safe zone. Tensions between the two Nato allies centre on a fundamental disagreement over the SDF, which controls the area on the Syrian side, from the Euphrates River to the Iraqi border.

The SDF, backed by US airpower and technical support, recaptured swathes of Syria’s northeast from Isis. The militia’s largest contingent is a Kurdish militia called the People’s Protection Units (YPG). While the US considers the YPG an ally, Turkey views it as a terror organisation and a branch of the outlawed Kurdistan Workers’ Party, which has fought the Turkish state for decades.

US Syria envoy, James Jeffrey, said last week that Washington is “committed to those who have fought with us not being attacked and not being harmed by anyone. The president made that clear publicly.”

Turkey wants its troops to control a 19-25 mile-deep zone inside Syria, while the US is arguing for a much smaller zone. But the SDF argues a unilateral incursion by Turkey would be seen as an occupation, and would be met with force.

“If the Turkish state does not choose the dialogue for a solution, we will be prepared for war,” SDF commander Newroz Ahmed said on Monday.

“If an attack is launched on any region, this attack will not be limited to this region. Rather, the long border with the Turkish state will become a region of war,” she added.

The Kurdish-led administration that controls the area said a Turkish attack would risk a resurgence of Isis, just months after the caliphate was defeated.

“These threats pose a danger on the area and on a peaceful solution in Syria, and any Turkish aggression on the area will open the way for the return of Daesh [Isis], and that aggression will also contribute to the widening of the circle of Turkish occupation in Syria,” it said in a statement.

The US has tried to act as a mediator between its two allies, but Ankara has grown frustrated with the Trump administration for stalling the plans for a safe zone. After initially refusing any Turkish role in the proposed safe zone, analysts say the SDF may be forced to accept a joint US-Turkey operation.

“The US team, after several months of stalling Turkey, now believes that the only thing that will keep the Turkish army from invading is to allow Turkish military units to patrol northern and eastern Syria with the Coalition,” Nicholas Heras, a fellow at the Centre for a New American Security think thank, told The Indepdendent. 

“The feeling on the US side is that if they give Erdogan the ‘win’ of forcing a Turkish military presence in some areas that are east of the Euphrates, in chaperoned patrols with the US and perhaps French forces, then the threat of further Turkish military action can be averted. The US is not asking the SDF if it accepts a Turkish military presence, it is telling the SDF this is a fait accompli. In effect, the Americans are telling the SDF that a limited Turkish military presence in some areas of the Euphrates, is the only thing that will ward off Turkey from destroying them,” he said.

Turkey’s defence ministry said later on Monday that “today’s part of negotiations with the US military officials on the planned establishment of the Safe Zone in the north of Syria has been completed.

“Negotiations will continue tomorrow at Turkish Ministry of National Defense HQ in Ankara,” the ministry wrote on Twitter.