Countries warn of potential dangers of autonomous weapons systems they say are at risk of violating international and humanitarian law

“Killer robots” – autonomous weapons systems that can identify and destroy targets in the absence of human control – should be strictly monitored to prevent violations of international or humanitarian law, nations from around the world demanded on Thursday.

The European Union, France, Spain, Austria, Ireland, the Netherlands, Croatia, Mexico and Sierra Leone, among other states, lined up at a special UN meeting in Geneva to warn of the potential dangers of this rapidly advancing technology. Several countries spoke of the need for ongoing scrutiny to ensure that the weapons conformed to the Geneva conventions’ rules on proportionality in war.

The Spanish delegation went further, invoking the possibility of a new arms race as developed countries scrambled to get ahead. Ireland, the Netherlands and other countries called for “meaningful human control” of lethal weapons to be enshrined in international law, although the meeting also admitted that the precise definition of that principle had yet to be clarified.

The Geneva meeting was the second major gathering of world powers this year to discuss the looming threat or possibility of fully self-operating lethal weapons. As such, it was an indication of mounting global concern about the technology, as its adoption by military forces gathers apace.

The US, the leader in the field, has already switched most of its aerial surveillance capabilities to unmanned aircraft – though the drones are still controlled by human pilots. It is a natural next step for the US air force to develop systems that can both deliver and then operate missiles and bombs robotically, with only minimal human intervention.

The New York Times reported this week that Lockheed Martin has developed a long-range anti-ship missile for the US air force and navy that can fly itself, with no human touch, for hundreds of miles, changing its flight-path autonomously to avoid radar detection. Britain, Israel and Norway already carry out attacks on radar installations, tanks and ships using autonomous drones and missiles, the paper said.

At the previous Geneva meeting on killer robots, Christof Heyns, the UN special rapporteur on extrajudicial, summary or arbitrary executions, called for an outright ban. “Machines lack morality and mortality, and as a result should not have life and death powers over humans,” he said.

Human Rights Watch, which is a co-founder of the Campaign to Stop Killer Robots, told Thursday’s plenary that a ban was the only practical solution. The group lamented the fact that the UN had spent only eight or nine days over the past two years focused on an area that was fast-moving and raised huge legal and ethical issues.

“There is a sense of urgency about how we deal with killer robots. Technology is racing ahead,” it said.

Regulation of autonomous weapons falls under the so-called “convention on certain conventional weapons” or CCW – a part of the Geneva conventions that deals with the impact of the tools of war on civilian populations. Under CCW, weapons that are deemed to affect civilians indiscriminately or to cause inhumane suffering to combatants can be banned or heavily restricted.