Leading researchers have sent out yet another appeal to restrain "killer robot" technology and sought a ban on AI-developed autonomous weapons that could drive the next revolution in warfare.

Now is the right time to get in place a ban, say over 1,000 researchers including Stephen Hawking, Elon Musk, Steve Wozniak, Jaan Talinn and Naom Chomsky, in the open letter which will be presented at the International Joint Conference on Artificial Intelligence in Beunos Aires on 28 July.

Like the historic ban on exploding bullets and more recently, the ban on blinding lasers which while used in medicine is not allowed as arms sale, they call for a ban on AI weapons.

The letter warns of a global arms race if any major military power pushes ahead with AI weapon development. The endpoint is the autonomous weapons will "become the Kalashnikovs of tomorrow", they warn.

Cheap to mass produce and ideal for tasks such as assassinations, destabilising nations, or selectively targeting ethnic groups, all that an autonomous weapon would require is a smartphone-style processor, cameras and a gun mounted on beefed-up versions of the quadcopters now commercially available, says the letter.

What is preventing that now is the availability of artificial intelligence software.

AI technology has already developed autonomous weapons described as the third revolution in warfare, after gunpowder and nuclear arms.

Going from existing drones to decision-making machines that engage targets is merely one small step. A US army research report has predicted that "swarms of robots that would act independently or collaboratively as they undertook a variety of missions" would be available by 2050.

The key question for humanity today is whether to start a global AI arms race or to prevent it from starting, write the experts in the letter, urging the UN to support a ban on offensive autonomous weapons systems.

Hawking and Musk have been vocal about the potential dangers of artificial intelligence, with Hawking even warning of AI spelling end to the human race.

Experts have warned of the dangers from AI weapons that could threaten human dignity and leave humans defenceless. Oxford University lists AI among top 12 threats to humanity.