The CEO of Tesla Motors and SpaceX joins 116 experts from 26 countries in making warning letters stating that the use of autonomous weapons would encourage a third revolution in war.
Not long ago, the UN decided to start a formal discussion on the use of autonomous or robotic weapons, such as drones, tanks and automatic rifles.
"Once developed, deadly autonomous weapons will allow for war on a larger scale and faster than any human can understand," reads the letter, as quoted by CNET.
"The weapon can be a tool for the spread of terror, used by terrorists and criminals against unhelpful societies and the weapons can be hacked for false use. We do not have long to act.As soon as this Pandora's box is open, it will be difficult to close."
Research in artificial intelligence a term commonly used on machines, computers or systems that have intelligence like humans are attracting the attention of big technology companies like Google and Facebook.
One use of AI is on weapons, including unmanned aircraft, guard robots and missile defense systems.
Musk is optimistic in the use of technologies such as solar power, space exploration and electric cars.
But he continues to show robotic worries with AI will threaten human existence. Although many people in the technology field believe AI will benefit humans, Musk has several times expressed his concerns.
In 2014 Musk revealed that he feared the uncontrolled AI would pose a threat to humans like in the movie The Terminator. Not long ago Musk even had time to compete with Facebook CEO, Mark Zuckerberg.