Elon Musk on Wednesday cast doubt on a $500 billion AI project announced by US President Donald Trump, saying the money promised for the investment actually wasn?t there.

The comments were a rare instance of a split between the world?s richest man and Trump, with Musk playing a key role in the newly installed administration after spending $270 million on the election campaign.

In his first full day in the White House, Trump on Tuesday announced a major investment to build infrastructure for artificial intelligence led by Japanese giant SoftBank and ChatGPT-maker OpenAI.

Trump said the venture, called Stargate, ?will invest $500 billion, at least, in AI infrastructure in the United States.?

But in a post on his social media platform X, Musk said the main investors ?don?t actually have the money.?

?SoftBank has well under $10B secured. I have that on good authority,? Musk added in a subsequent post.

Musk?s sideswipe could be particularly targeted at OpenAI, the world?s leading AI startup that Musk helped found, before leaving in 2018.

The Tesla boss and OpenAI chief executive Sam Altman, who was present at the White House on Tuesday, have been mired in a serious feud, with Musk opening repeated lawsuits against the company behind ChatGPT.

OpenAI is one of the world?s highest valued startups, but loses money on the high costs of turning out its expensive technology.

According to the Wall Street Journal, cloud giant Oracle, which is also involved, has about $11 billion in cash and securities. SoftBank has roughly $30 billion of cash on hand.

The Stargate project is committed to invest an initial $100 billion and up to $500 billion over the next four years in the project. (AFP)

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