WASHINGTON—Elon Musk said on Saturday he will start training if the mixed martial arts cage fight he has provoked with fellow billionaire media mogul Mark Zuckerberg takes shape.

Twitter owner Musk wrote on Twitter on Tuesday he was up for a cage match in Las Vegas with Zuckerberg, CEO of Facebook parent Meta, who has trained in jiu-jitsu.

“I haven’t started training yet. So if this does happen, I will,” Musk said in a talk on Twitter with Ashlee Vance, the author of a book on Musk and the space race.

The match “might actually happen” said Musk while attending a birthday party in Europe, adding it was possible that it could go badly if Zuckerberg takes the match seriously.

Musk also said SpaceX investments in the rocket Starship, the debut flight of which exploded over the Gulf of Mexico in April, may approach $3 billion this year.

Musk said SpaceX was working on improvements to Starship.