San Francisco, Dec 8 (IANS): Tesla and SpaceX CEO Elon Musk said that the civilisation will "crumble" if people do not start having more kids, media reports say.

According to The New York Post, Musk said he thinks one of the biggest risks to civilisation is the low birthrate and the rapidly declining birthrate.

"And yet, so many people, including smart people, think that there are too many people in the world and think that the population is growing out of control," the father of six said at the Wall Street Journal's annual CEO Council.

"It is completely the opposite. Please look at the numbers -- if people don't have more children, civilisation is going to crumble, mark my words," he added.

The billionaire's remarks came in response to a question about how his company's not-yet-released Tesla Bot could solve labour issues.

At an unveiling event in August, Musk said the 5-foot-8-inch, 125-pound robot could be ready as soon as next year and it will have a "profound" impact on the economy by driving down labour costs.

At the WSJ event on Monday, he added that the Tesla Bot could be a "generalised substitute for human labour over time" -- which will become increasingly critical for businesses if the human labour supply falls.