ISTANBUL — Turkish President Recep Tayyip Erdogan took his case for a "safe zone" in northeast Syria to the world stage this week, telling the United Nations General Assembly that as many as three million refugees could be moved to an area of the war-torn country now controlled by US-allied Kurds.

Turkey wants to create an initial “peace corridor” 30 kilometers (19 miles) deep and 480 kilometers (300 miles) long east of the Euphrates River to repatriate Syrians who have fled the eight-year war that has killed a half-million people, Erdogan told world leaders gathered for the UN’s annual meeting on Tuesday.

“With international support, we can settle two million Syrians here, and if we expanded the area’s depth to the Deir ez-Zor-Raqqa line, we can lift the number of Syrians from Europe and other parts of the world returning home to three million. Turkey is determined to achieve this issue and has started its preparations,” he said.

Turkey has welcomed 3.6 million Syrians fleeing violence since 2011 and has spent close to $40 billion caring for them. But public discontent with the foreigners is brewing, especially amid a painful economic downturn, and the buffer zone could serve as a release valve if the government can repatriate Syrians there as well as its best bet to stymie Kurdish autonomy.