"When you see the success, frankly, that the navy has had in terms of lowering the numbers of people on ships, are there functions in the brigade that we could automate - robots or manned/unmanned teaming - and lower the number of people that are involved, given the fact that people are our major cost?"
But there are no immediate plans for robots to be deployed with lethal firepower. Huw Williams, an expert on military robots and unmanned vehicles at the defence publication IHS Jane's, said armies were focusing on investigating robot vehicles for transport. "If you have a lead manned vehicle, you could have several unmanned vehicles following ... or a train solely of unmanned vehicles."
Several robot ground vehicles have already been tested in Afghanistan, including the Squad Mission Support System, a six-wheeled robotic buggy to carry soldiers' kit. Last year the British Army announced the purchase of dozens of remotely controlled robotic diggers.
The rise of the new technologies has provoked fears of future battlefields one day stalked by unaccountable robotic killing machines, and in 2012, Human Rights Watch called for a pre-emptive ban on killer robots "before it's too late".
US General Stanley McChrystal, who oversaw Nato forces in Afghanistan, told the BBC's Today programme yesterday that America's drones created "a tremendous amount of resentment".