I believe there is no deep difference between what can be achieved by a biological brain and what can be achieved by a computer.
"It therefore follows that computers can, in theory, emulate human intelligence - and exceed it."
Professor Hawking said the potential benefits were great and that AI could "finally eradicate disease and poverty".
"In short, success in creating AI could be the biggest event in the history of our civilisation," he said. "But it could also be the last unless we learn how to avoid the risks."
Alongside the benefits, AI in the future "could develop a will of its own - a will that is in conflict with ours", he added.