Aircraft that fail to comply with procedures within a restricted airspace zone around the Olympic site in London could be subject to "lethal force" from the military.
RAF Typhoon fast jets and RAF Puma helicopters with snipers armed with hi-tech rifles will be among the military aircraft patrolling the restricted zone which comes into force from Saturday.
Intercepted aircraft will be expected to comply with the directions of the military aircraft.
"As a last resort, we will have lethal force as an option," said Air Vice-Marshal Stuart Atha, the Olympics air security commander.
Asked who would give the order for lethal force to be used, AVM Atha said: "The highest level of Government makes that decision."
He said taking lethal action would be a "worst-case scenario" and that a best-case scenario would be to intercept and gain knowledge of the seriousness of the situation away from the built-up area of London.
AVM Atha was speaking at RAF Northolt in west London where some of the aircraft that will help patrol the restricted area were on display.
The restricted zone, in operation from midnight July 13 to August 15, comprises a small inner zone covering central London and the Olympic site in Stratford, east London, and a large zone covering a swathe of south-east England.
The restricted zones are designed for general aviation which includes light aircraft, gliders and balloons. No commercial flights will be affected. There will also be restrictions at the Olympic sailing venue at Weymouth in Dorset from Saturday until September 8.