The physicist, who has previously spoken out about the risks of AI, joined 1,000 other leading scientists and businessmen in signing an open letter from the Future of Life Institute.
The letter, presented at a major conference in Argentina, suggests the ability to create weapons which think for themselves, unlike remote-controlled drones, is “feasible within years”.
Apple co-founder Steve Wozniak and SpaceX entrepreneur Elon Musk were among the signatories who warned that developing autonomous weapons would be a “bad idea”.
It said: “If any major military power pushes ahead with AI weapon development, a global arms race is virtually inevitable, and the endpoint of this technological trajectory is obvious.
“Autonomous weapons are ideal for tasks such as assassinations, destabilising nations, subduing populations and selectively killing a particular ethnic group. We believe a military AI arms race would not be beneficial for humanity.”
Hawking has previously said that the rise of AI could see the human race become extinct.