The United States is planning a "full" and "rapid" withdrawal of US forces from Syria as it nears the end of its campaign to retake all of the territory once held by Islamic State, according to CNN.Russia called for the withdrawal today, saying the US's presence is a roadblock to a peace settlement in Syria.The decision would upend assumptions about a longer-term US military presence in Syria, which US Defense Secretary Jim Mattis and other senior US officials had advocated to help ensure Islamic State cannot reemerge.