Washington and Ankara have been at odds over plans for the region in northeastern Syria where the U.S.-backed force led by the Syrian Kurdish YPG militia have been fighting Islamic State.

Ankara considers the YPG a terrorist group because it says it has links to Kurdish militants in Turkey.

Turkey and the United States have set up a joint operation center for the planned zone along the border with Turkey but have disagreed over the size of the zone or the command structure of the forces to operate there.

“We do not have much time or patience regarding the safe zone which will be established along our entire border east of the Euphrates (river),” Erdogan said in a speech at a graduation ceremony at the National Defense University in Istanbul.

“If our soldiers do not control the region within a few weeks, we will put our own operation plan into effect,” he said, adding that he wanted Turkish soldiers to start setting up the “safe zone” in two to three weeks.

According to Reuters he did not say what the operation plan would entail, but he has previously warned that Turkey would mount a cross-border offensive on its own to clear the YPG militia from its border if necessary.

U.S. President Donald Trump proposed the safe zone last year, having announced plans to withdraw U.S. special forces from northern Syria but he later suspended the plan to ensure Washington’s Kurdish allies would be protected.

An official in the YPG-led alliance said on Tuesday that the YPG would pull forces and heavy weapons from a strip along Syria’s border with Turkey under U.S.-Turkish deals.

The YPG withdrew from the Tal Abyad and Ras al-Ain border positions in recent days, proving it was serious about ongoing talks, the Kurdish-led authority in north and east Syria said.

Ankara and Washington have also fallen out over Turkey’s purchase of Russian S-400 missile defense systems, prompting Washington to begin removing Turkey from its program for manufacturing F-35 jets, which Turkey also planned to buy.

Reporter’s code: 50101