Russia slammed that move as a violation of international law.
"These pro-regime forces, they have halted their advance. If they resume their advance on coalition forces, they will be considered a hostile threat, and coalition forces will defend themselves," Davis told reporters.
"There is one area — they are still in it — but they are not moving, and I understand that they are working to leave."
"The deconfliction we have with Russia is working well. We have been communicating through the Russian channel about these concerns [about the militia]," Davis told reporters on Tuesday.
The United States and Russia signed the bilateral memorandum of understanding in October 2015 to ensure their flight safety during combat missions over Syria.