ROME (AFP) - American billionaire Elon Musk on Saturday (July 2) broke his silence on the Twitter social media site, which he plans to buy, posting a picture of himself with Pope Francis.

"Honored to meet @Pontifex yesterday," Musk tweeted next to a photograph of him and four of his children with the Argentinian-born pontiff.

The location and details of the meeting were not specified by the Tesla and SpaceX boss, while the Vatican did not comment on his private audience with Pope Francis.

Last week, Musk said that his US$44 billion (S$60 billion) move to take over Twitter remained held up by "very significant" questions about the number of fake users on the social network.

The richest man in the world added then that there were also questions about Twitter's debt and whether shareholders will vote for the deal.