Tesla’s Chief Executive Officer Elon Musk on Monday said that the race between global powers to acquire artificial intelligence could be the reason for World War III. In a tweet, Musk referred to Russian President Vladimir Putin’s statements last week that the country that would come to lead the world in AI would also be the most powerful in the globe.

Musk, who is also the CEO of Space Exploration Technologies Corporation or SpaceX, has warned of AI bringing the world to a doomsday-like scenario in the past too. Last month, he was one of 116 AI experts who wrote to the United Nations seeking to ban lethal autonomous weapon systems or killer robots, which can identify and attack targets without human intervention.

In July, speaking to United States governors, Musk had said that “AI is a fundamental existential risk for human civilisation,” The Independent reported. “I have exposure to the most cutting-edge AI and I think people should be really concerned about it,” he said. “I keep sounding the alarm bell but until people see robots going down the street killing people, they don’t know how to react because it seems so ethereal.”