Killer robots might sound like the stuff of science fiction, but they're alarmingly close to becoming a reality. A new report from the United Nations Human Rights Commission suggests that lethal autonomous robots need to be regulated before they become the military weapons of the future.

The report — which was debated at the Human Rights Council in Geneva on May 29 — states that the United States, Israel, the United Kingdom, South Korea and Japan all possess lethal robots that are either fully or semi-autonomous.

Some of these machines — or "lethal autonomous robotics" (LARS), as they are called in the report — can allegedly choose and execute their own targets without human input.

The author of the report, South African human rights professor Christof Heyns, calls for a worldwide moratorium on the "testing, production, assembly, transfer, acquisition, deployment and use" of these killer robots until further regulations are put in place to govern their use.

According to the Associated Press, the report cites at least four examples of fully or semiautonomous weapons that have already been developed around the world. The report includes the U.S. Phalanx system for Aegis-class cruisers, which automatically detects, tracks and engages antiship aircraft.

Other examples of existing LARS include Israel's Harpy, an autonomous weapon that detects, attacks and destroys radar emitters; the U.K's Taranis, a jet-propelled drone that can autonomously locate targets; and South Korea's Samsung Techwin surveillance system, which autonomously detects targets in the demilitarized zone between North and South Korea.

While the U.N. report focuses mainly on LARS, it also decries the recent upsurge in the use of unmanned aerial vehicles — or drones — by the U.S. military, and other nations.

"[Drones] enable those who control lethal force not to be physically present when it is deployed, but rather activate it while sitting behind computers in faraway places, and stay out of the line of fire," Heyns wrote.