Billionaire and 2020 presidential prospect Mark Cuban is warning of a dystopian future in which intelligent machines put humans at risk of extinction.

"Autonomous weaponry is the ultimate threat to humanity," Cuban, the owner of the Dallas Mavericks, tweeted Monday.

He was responding to fellow billionaire, Tesla CEO Elon Musk, who raised the alarm over a potential arms race between superpowers over artificial intelligence superiority at a "national level," which, he postulated, would "most likely cause" World War III.

Cuban, who according to Forbes is worth more than $3 billion, has previously discussed the threat of smart robots in terms of killing jobs. Instead of rising against the machines, Cuban advocated in a December 2016 blog post that the U.S. should invest more in companies that make robotics to stay competitive with other countries.

Cuban has repeatedly flirted with the idea of making a run against President Trump in 2020, whom he has criticized multiple times since the inauguration.

There's some evidence to suggest he could pose a threat. A recent poll from the left-leaning Public Policy Polling showed Cuban ahead of Trump in a head-to-head contest.

"These are always entertaining," Cuban wrote in an email to Business Insider after the poll was released. "As I have said before, I would only run if I can come up with solutions for healthcare, the plight of working families, and reducing the stress levels of our country. It's possible. When I have something to offer, I will."

The latest round of alarms from Cuban and Musk began when reports came out of Russia that President Vladimir Putin told students Friday that A.I. is the future of mankind, and said, "Whoever becomes the leader in this sphere will become the ruler of the world."