Syria

"We have to always be concerned with this," the former defense secretary said.

"We have reports already of indiscriminate fire landing near American forces," Defense Secretary Mark Esper said.

Turkish officials say the U.S. position was not targeted.

"De-escalate the situation before it becomes irreparable," Pentagon chief spokesman Jonathan Hoffman said.

The stop comes in response to threats from Turkey.

Turkey has begun an invasion of a Syrian region evacuated by U.S. troops.

The Pentagon came out in opposition to Turkey's plan to invade northeastern Syria.

The U.S.-backed SDF has begun pulling back and destroying fortifications in northern Syria.

The report also warned that the SDF could look for "alternate partnerships and resources" as U.S. influence wanes.

The civil war is now largely stalemated, as are many of the secondary issues that were linked to it.