U.S. officials say Washington is considering extending support to thousands of Syria fighters, possibly with arms and air strikes, to help them push ISIS from a strategic pocket of Syrian territory along the Turkish border, Reuters reported.

U.S. backing for the plan would come as moderate rebels in Syria, some trained and backed by the United States, say they have been targeted by Russian air strikes, raising tensions between Washington and Moscow.

A decision, the officials said, would likely be made as part of a comprehensive overhaul of the U.S. military’s support for rebels to fight ISIS following setbacks that have all but killed a “train-and-equip” program.

The proposal under consideration is for the United States and Turkey to support an amalgamation of largely Arab fighters and would include members of multiple ethnic groups, U.S. officials say.

The aim of the operation would be to push ISIS forces from a 90-km (56-mile) stretch of Syria’s northern border running east toward the Syrian city of Jarabulus, about 130 km northwest of the ISIS’s declared capital of Raqqa. The area is west of the Euphrates river that dissects the Syria-Turkey border.

STRATEGIC VALUE

Chris Kozak, a Syria analyst at the Washington-based Institute for the Study of War, said the territory was strategically valuable to ISIS, serving as its last significant point of access to the northern border with Turkey.

U.S. assistance could include everything from air strikes, to offering equipment and even arms, if approved, the military official said, adding that the different levels of U.S. knowledge about the fighters has added complexity to the review.

Turkey and the United States agreed to take the territory in July as part of an agreement under which Ankara allowed the United States to use its bases for strikes against ISIS. Turkey also started carrying out air strikes on ISIS targets in Syria.

The U.S. administration, which is seeking to avoid a proxy war with Russia, has so far signaled no intention to protect Syrian rebels from Russian bombing.

At a news conference on Friday, Obama acknowledged that the U.S. military’s train and equip program had not achieved its goals but said he would continue to work with Syria’s moderate opposition.

“We are going to continue to go after ISIL. We are going to continue to reach out to a moderate opposition. We reject Russia’s theory that everybody opposed to Assad is a terrorist,” Obama said.

U.S. officials have told Reuters that a review is underway that could also result in scaling back and reenvisioning Washington’s struggling program to train and equip moderate rebels. About 80 graduates are deployed in Syria now and dozens are still in U.S. training, but the Pentagon has stopped drawing recruits from the Syrian battlefield during the review.

At the same time, the Obama administration is weighing the possibility of supporting another, separate rebel push east of the Euphrates river that includes largely Kurdish forces, the military official said.

That group, known as the Syrian Arab Coalition, would push south toward Raqqa, the official said.