The United Nations Human Rights Council has heard an appeal for a freeze on the development and use of killer robots.

The lethal autonomous robots (LARs) are pre-programmed to kill or destroy and, unlike drones, are not controlled by humans once on the battlefield.

Key points Lethal autonomous robots are pre-programmed to kill

Lethal autonomous robots are pre-programmed to kill Can make their own decisions and do not need to be controlled by humans

Can make their own decisions and do not need to be controlled by humans Supporters say they could save soldiers' lives

Supporters say they could save soldiers' lives Human rights groups want a complete ban

The technology is being developed in the United States, Britain and Israel, although none have actually used it yet.

During a debate at the UN Human Rights Council, special rapporteur Professor Christof Heyns said machines lacking morality should not have life-and-death powers over humans.

"War without reflection is mechanical slaughter," he said.

"In the same way that the taking of any human life deserves as a minimum some deliberation, a decision to allow machines to be deployed to kill human beings worldwide, whatever weapons they use, deserves a collective pause, in other words a moratorium."

Professor Heyns warned that the use of lethal robots could enable war crimes to go unpunished.

"Their deployment may be unacceptable because no adequate system of legal accountability can be devised," he said.

"LARs can potentially be also used by repressive governments to suppress internal domestic opponents.

"Do we want a world in which we can be killed either as combatants or as collateral damage by robots with an algorithm which takes the decision?

"It's this issue of diminishing human responsibility that concerns me."

Human rights groups want complete ban

A fake killer robot pictured during a protest in London ( AFP: Carl Court, file photo )

Human rights groups are taking an even harder line and calling for a complete international ban of the lethal robots before they ever get to the battlefield.

"The international community should consider a complete ban on LARs," Pakisan's council delegate Mariam Aftab said.

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"We believe the experience with drones shows that once such weapons are in use, it is impossible to stop them."

Supporters of LARs say they offer life-saving potential in warfare because they can get closer than troops to assess a threat properly.

The US acknowledged that lethal autonomous weapons could present policy and ethical issues and last November Washington imposed a 10-year human control requirement.

"We call on all states to proceed in a lawful, prudent and responsible manner when considering whether to incorporate automated and autonomous capabilities in weapons systems," said US delegate Stephen Townley.

Britain's council delegate said existing legal provisions were sufficient.

The US Navy made aviation history on May 14 by launching an unmanned jet - the X-47B stealth drone by Northrop Grumman - from an aircraft carrier for the first time, taking an important step toward the expanded use of drones.

Human Rights Watch, in its campaign against killer robots, cited the X-47B as one of several weapons that represent a transition toward development of fully autonomous arms.

Samsung security robots deployed in the demilitarised zone between North and South Korea are operated by humans, but have an automatic mode.

ABC/AFP