Elon Musk confirmed on Thursday that he is fathered twins with an executive at his brain chip company Neuralink just weeks before welcoming his second child with Canadian pop star Grimes.

"Doing my best to help the underpopulation crisis," the Tesla CEO tweeted on Thursday.

"A collapsing birth rate is the biggest danger civilization faces by far."

Musk in recent weeks has frequently tweeted about declining birth rates in the Western world.

When a Twitter user asked father-of-nine Musk what was driving the trend, he replied: "Far too many people are under the illusion that Earth is overpopulated, even though birth rate trends are so obviously headed to population collapse."