The United Nations and Red Cross warned Tuesday the world is "dangerously close" to a future where autonomous weapons -- so-called "killer robots" -- could target humans, and issued an urgent appeal for international regulations. The warning follows a call in 2023 from UN Secretary General Antonio Guterres and Mirjana Spoljaric, president of the International Committee of the Red Cross, for countries to establish specific bans and restrictions on the rapidly developing technology by this year. "Today, we renew this call with even greater urgency," they said in a joint statement, adding that while their "fundamental concerns remain unchanged... the risks have intensified.” "We are now dangerously close to crossing a moral red line: the autonomous targeting of humans by machines," they warned. Lethal autonomous weapon systems are generally understood as weapon systems that select targets and apply force without human intervention. There has to date been no confirmed use of fully autonomous weapons. But with global tensions soaring and conflicts raging in the Middle East and Ukraine, where drone warfare has become a major feature of the battlefield, fears abound that it could soon happen. There is currently no specific treaty on autonomous and artificial intelligence-enabled weapons. "Autonomous weapon systems are not part of a distant future: a race towards greater autonomy in weapons systems is already well under way," AFP quoted Guterres and Spoljaric as saying. "Future generations will ask whether leaders acted when there was still a chance to set limits before these weapons proliferated beyond control." They highlighted that scientists and engineers involved in developing such systems had, in many cases, raised the alarm themselves. "When the architects of this technology are calling for limits, states cannot afford to remain passive," they said. Discussions have been running for a decade around a possible future treaty regulating the use of autonomous weapons. After three years of discussions, countries are due to decide in November whether to launch full-on treaty negotiations. The UN and Red Cross chiefs called for "political courage,” saying: "A failure to act quickly and decisively will cost lives." The need for clearly defined rules was "urgent,” they said, insisting that "innovation must serve humanity -- not endanger it.”