The U.S. will send a small number of U.S. special operations forces into Syria as part of a shift in its strategy against ISIS, White House officials announced Friday.

President Barack Obama has authorized a contingent of fewer than 50 commandos to deploy into northern Syria and work with moderate opposition forces who are fighting the militants.

While the White House has consistently said it would not put U.S. boots on the ground, White House spokesman Josh Earnest insisted that they will be there in a "train, advise and assist mission" — and not in a combat role. "It will not be their responsibility to lead the charge up the hill," he said. But he acknowledged they will be in a perilous situation: "There is no denying the amount of risk they are taking on here." More from NBC News: 'Raqqa Is being slaughtered silently' activist killed in Urfa, activist group says

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Earnest called the additional forces an "expansion" but not a "change" in U.S. strategy against ISIS. He was unable to detail what the special operators will do, citing security concerns. He also didn't deny the suggestion that the increase in forces would not turn the situation around in Syria, where President Bashar Assad remains in power.

Obama "has been quite clear that there is no military solution to the problems that are plaguing Iraq and Syria — it's a diplomatic one," Earnest said.



A senior U.S. official earlier told NBC News that the special operations forces will work alongside groups with a "proven track record" of fighting ISIS. That could include working with Kurdish and allied actors who have come together under the umbrella of the "Syrian Democratic Forces," the official said, speaking on condition of anonymity before the announcement was not yet public.

Rep. Mac Thornberry, chair of the House Armed Services Committee, said the expected announcement made clear the White House was feeling the pressure of a "failed policy" against ISIS.

"I'm concerned that the administration is trying to put in place limited measures — too late — that are not going to make a difference," he told NBC News. "I don't see a strategy towards accomplishing a goal, I see an effort to run out the clock without disaster."

