Defense Secretary Michael Fallon said today that British Reaper drones and Rivet Joint surveillance aircraft would be starting operations "very shortly."
In a written statement to lawmakers, Fallon said the aircraft would "gather intelligence as part of our efforts to protect our national security from the terrorist threat emanating from there."
He said the drones were not authorized to use weapons in Syria.
Britain's Parliament voted last month to approve British airstrikes against IS forces in Iraq, but not in Syria.