The boss of Gatwick Airport has refused to rule out the possibility of future drone disruption once the military leave.
Gatwick chief operating officer Chris Woodroofe said there is currently no commercially available equipment he could put in place to neutralise the threat.
Speaking outside the airport on Friday morning, he apologised to passengers and said he hopes flights will be operating normally by Saturday.
"It's a criminal act, deliberate act," he said.
"This is an unprecedented issue. This isn't a Gatwick Airport issue. It's not even a UK issue. It's an international issue."
The runway reopened on Friday morning having been shut for around 36 hours after multiple drone sightings inside its perimeter, while the police investigation is ongoing.
"What we need to be doing going forward is work with technology providers and with the Government to enhance our ability to address the risk posed by drones to airports," said Mr Woodroofe.
"We have been working with technology providers ourselves for the last 12 months but stood here today, there is no commercially available airport licensed proven technology that I could implement."
Asked if there is anything in place to stop this happening again once the military leave, he said: "My number one priority is going to be the safety of our passengers. And so, if the drone comes and endangers an aircraft then we will suspend runway operations because safety is the number one priority."
Mr Woodroofe said the airport was operating at almost normal runway conditions on Friday, although airlines were still dealing with the fallout from the disruption.
"So what we'll be doing today is recovering their operations so by tomorrow we are back to standard operation and continue to recover the situation for our passengers," he said.
"Last night working with a number of government agencies and the military we were able to put in place a number of additional mitigating actions which gave me the confidence to re-open Gatwick Airport this morning.
"We now have passengers arriving and departing. We are very much hoping to run a schedule today. It's going to be disruptive. Passengers are going to be delayed. And every passenger should check with their airline before they come to the airport.
"We are very much hoping to get 100,000 passengers on their way to destinations and back into Gatwick Airport so we can begin to recover from this 36 hour incident and get those passengers to their destinations in time for Christmas."