'Killer robots' have long been depicted in movies, such as the Terminator franchise, but several nations are now developing real AI controlled weapons Getty images

The U.S. and Russia were among a group of countries which blocked further discussion of a proposed UN measure banning the use of so-called "killer robots."

During a week long summit in Geneva, a group at the United Nations' Convention on Conventional Weapons proposed holding formal discussions on the use of weapons which require no human operators and are controlled by artificial intelligence. The formal discussions could have paved the way for a treaty banning use of the weapons.

However a groups of member states­—led by the U.S. and Russia and including South Korea, Israel and Australia—were among countries opposed to formal discussions that could lead to a ban treaty, reported Politico.

"It's a disappointment, of course, that a small minority of large military powers can hold back the will of the majority," Mary Wareham, coordinator of the Campaign to Stop Killer Robots, told the publication.

Under the convention's rules, consensus between members must be achieved on the course of future actions and discussions.

"Any one state can block any progress," Wareham said. "And that's what's happened here."

Several countries are currently developing autonomous weapons systems, with Russian defense contractor Kalashnikov last year announcing the development of a neural networks based system capable of making decisions on when to fire weapons.

The U.S. Department of Defense released a video showing a swarm of autonomous drones flying over California in military exercises. It announced recently it is developing drones that can identify targets autonomously using AI.

26 countries have called for a prohibition on fully autonomous weapons, including Austria, Belgium and China. They joined thousands of scientists, AI experts and 20 Nobel Peace Prize laureates in supporting a ban.

In a report published jointly by Human Rights Watch and Harvard Law School's International Human Rights Clinic in August, it was alleged that the use of killer robots could breach the Martens Clause, a fundamental principle of international law. Under the clause, states must consider the "principles of humanity" and the "dictates of public conscience" when waging war.

Members of the UN Convention on Conventional Weapons have agreed to hold further non-binding talks on the issue. A decision on future work on the weapons will be made at the convention's November summit in Geneva.