Country officials and campaigners have expressed disappointment after United Nations talks on autonomous weapons systems – known as "killer robots" – stopped short of launching negotiations into an international treaty to govern their use following opposition from manufacturing states. Unlike existing semi-autonomous weapons such as drones, fully-autonomous weapons have no human-operated "kill switch" and instead leave decisions over life and death to sensors, software and machine processes. The regulation of the industry has taken on new urgency since a UN panel report in March said the first autonomous drone attack may have occurred in Libya. This week, UN Secretary-General Antonio Guterres encouraged the 125 parties to the Convention on Certain Conventional Weapons (CCW) to come up with an "ambitious plan" on new rules. But on Friday, the Sixth Review Conference of the CCW failed to schedule further talks around the development and use of the Lethal Autonomous Weapon Systems, or LAWS.