The withdrawal of assistance comes as the US-led military coalition battles the remaining elements of ISIS in the Middle Euphrates River Valley along the Syrian border of Iraq.

“Two-hundred million dollars of stabilization assistance for Syria is currently under review at the request of the President,” the official said in a statement to CNN. “Distinct from that amount, U.S. assistance for programs in northwest Syria are being freed up to provide potential increased support for priorities in northeast Syria, as will be determined by the outcome of the ongoing assistance review, including the D-ISIS campaign and stabilization efforts.”

While the US-led coalition has cleared the country’s northwestern region of ISIS, al Qaeda-linked groups such as the Nusra Front still maintain a foothold there, and Syrian President Bashar al-Assad’s government has been consolidating gains in territory there that it had lost to rebel forces, raising questions about what the US withdrawal of aid will mean for Syria’s future.