Elon Musk has expressed regret at some of his comments against US President Donald Trump after a public spat between the two former allies last week.

"I regret some of my posts about President [Donald Trump] last week. They went too far," Musk said in a post on his X platform.

He did not immediately specify which of the comments he regretted posting.

Musk spent some $300 million (nearly €263 million) on Trump's election campaign and initially spearheaded the controversial Department of Government Efficiency (DOGE) before stepping away from it late in May.

Why did Musk fall out with Trump?

The feud was sparked by Musk's opposition to Trump's tax and spending bill. Trump claimed that his former adviser's opposition to the bill was caused by its proposed elimination of tax credits for electric vehicles, which could affect Musk's Tesla automaker firm.

Musk claimed that he opposed the bill because it would increase the federal deficit.

In now deleted posts originally published on X, Musk attempted to link Trump to convicted sex offender Jeffrey Epstein.

"Time to drop the really big bomb: [Trump] is in the Epstein files. That is the real reason they have not been made public," Musk claimed without providing evidence.

Later, Trump threatened to cut Musk's government contracts in a post on his Truth Social platform.