Elon Musk is clashing with OpenAI CEO Sam Altman over the Stargate artificial intelligence infrastructure project touted by President Donald Trump, the latest in a feud between the two tech billionaires that started on OpenAI’s board and is now testing Musk’s influence with the new president.

Trump on Tuesday had talked up a joint venture investing up to $500 billion through a new partnership formed by OpenAI, the maker of ChatGPT, alongside Oracle and SoftBank.

The new entity, Stargate, is already starting to build out data centers and the electricity generation needed for the further development of fast-evolving AI technology.

Trump declared it “a resounding declaration of confidence in America’s potential” under his new administration, with an initial private investment of $100 billion that could reach five times that sum.

But Musk, a close Trump adviser who helped bankroll his campaign and now leads a government cost-cutting initiative, questioned the value of the investment hours later.

“They don’t actually have the money,” Musk wrote on his social platform X. “SoftBank has well under $10B secured. I have that on good authority.”

Altman responded Wednesday to say Musk was “wrong, as you surely know” and inviting Musk to come visit the first site in Texas that is already under construction.

“(T)his is great for the country. i realize what is great for the country isn’t always what’s optimal for your companies, but in your new role i hope you’ll mostly put (America) first,” Altman wrote, using a U.S. flag emoji to represent America.

Musk, an early OpenAI investor and board member, sued the artificial intelligence company last year, alleging it had betrayed its founding aims as a nonprofit research lab benefiting the public good rather than pursuing profits.

Then last year, Musk started his own rival AI company, xAI, that is building its own big data center in Memphis, Tennessee.