BEIRUT — Turkey and the United States have agreed on the outlines of a plan to rout the Islamic State group from a strip of Syrian territory along the Turkish border – a plan that opens the possibility of a safe haven for tens of thousands of displaced Syrians but one that also sets up a potential conflict with U.S.-backed Syrian Kurdish forces in the area.

The move further embroils Turkey, a key NATO ally, in Syria’s civil war, and also catapults it into a front-line position in the global war against IS.

A senior Obama administration official said Monday that U.S. discussions with Turkey about an IS-free zone focused on a 68-mile stretch still under IS control. The U.S. has been conducting airstrikes there, which will accelerate now that the U.S. can launch strikes from Turkish soil, the official said.

No agreement between Turkey and the U.S. has yet been finalized, said the official, who spoke on condition of anonymity under regulations.

Another U.S. official said earlier Monday that any joint military efforts with Turkey would not include the imposition of a no-fly zone. The U.S. has long rejected Turkish and other requests for a no-fly zone to halt Syrian government air raids, fearing it would draw U.S. forces further into the civil war. The official insisted on anonymity because this person was not authorized to publicly discuss the talks with Turkey.

While details of the buffer-zone plan have yet to be announced, Turkish Prime Minister Ahmet Davutoglu said Ankara and Washington have no intention of sending ground troops into Syria but wanted to see Syria’s moderate opposition forces replace IS near the Turkish border.

The discussions came amid a major tactical shift in Turkey’s approach to IS. After months of reluctance, Turkish warplanes started striking militant targets in Syria last week, and allowed the U.S. to launch its own strikes from Turkey’s strategically located Incirlik Air Base.