White House spokesman Josh Earnest told reporters Friday the move does not represent an attempt to topple the government of Syrian President Bashar Al-Assad.

"That was precisely the mistake the previous administration made," Earnest said, referring the U.S. invasion of Iraq. "That did not serve the interest of the United States and in some ways we’re still paying the price for that mistake."

Rather, he said, U.S. forces will focus their efforts improving rebel fortunes against ISIL. For the government in Damascus, Earnest said a "political solution" was necessary to remove Assad.

Earlier this week, Secretary of Defense Ash Carter announced U.S. plans to step up attacks against ISIL fighters in Iraq and Syria. The development comes despite repeated Obama administration assurances that the U.S. would not send troops into the country. But even before Friday's development, special forces have been on the ground in Syria in selective raids around the country.

The addition of new U.S. forces comes on the one-month anniversary of a bold Russian intervention on the side of the Assad regime. Unlike Moscow's intervention, the U.S. does not appear to have the explicit permission of Damascus to send troops into its borders — even if only in territory no longer controlled by regime forces.

Al Jazeera has learned that the U.S. mission will not be coordinating with either Russia or the Syrian regime, but that the troops will only be assisting their local ground partners in operations against ISIL — not the regime.

The move is also a shift in how the Obama administration is attempting to assist the moderate Syrian rebels, including the non-aligned Kurds. Earlier this month, the administration jettisoned a widely criticized $500 million program that sought to create a fighting force of some 5,000 rebels, but which only saw about 100 fighters enter combat in the country.

Although he wouldn't give an end date to the mission, Earnest said he "certainly wouldn't describe it as permanent." He acknowledged that the special forces soldiers would face dangerous conditions, but that the Department of Defense would "make it as safe as possible to operate there."

The Pentagon official told Al Jazeera: "The point is to get some guys on the ground. Get eyes on. Work with the units that are there fighting ISIL and see what more is possible. This is a start," the official said, "to gauge what’s possible and in the meantime help with operational planning."

The new policy comes the same day Secretary of State John Kerry is in Vienna alongside his counterparts from Russia, Saudi Arabia, Turkey, Iran and other world powers who are meeting with the aim of achieving a political settlement to help end the war in Syria.

Friday's talks in the Austrian capital included for the first time the participation of Iran, the chief backer — along with Russia — of Assad.

Correction: A previous version of this article stated that the U.S. forces being deployed to Syria were the same as a contingent of forces currently based in Iraq. That was incorrect, as the special forces are being sent from the U.S.

Al Jazeera and wire services. Jamie McIntyre contributed reporting from the Pentagon.