The friendship between the President of the United States and the world's richest man has crashed in flames and descended into mudslinging.The stoush, which began over a disagreement about national debt, peaked on Thursday when Elon Musk accused Donald Trump of not disclosing files relating to sex offender Jeffrey Epstein due to personal involvement.The allegation, presented without evidence, highlights the deepening rift between the two men and harks back to old reports about Mr Trump's links to the high-profile sex trafficker.Here's what to know.
Why are Trump and Musk fighting?
In short, it stems from a disagreement over a section of Mr Trump's One Big Beautiful Bill Act.
While the 1,038-page document proposes hundreds of changes, the one Mr Musk takes issue with is a plan to raise the federal debt ceiling by $US 4 trillion to $40 trillion.
Mr Musk argues that the government should be working to reduce its deficit and raising the debt ceiling would enable it to do the opposite.
Mr Trump suggested the Tesla billionaire also opposed a measure that would scrap electric vehicle subsidies, telling his social media followers Mr Musk "just went CRAZY" when he axed the subsidies for "Electric Cars that nobody else wanted".
What did Musk say about the Epstein files?
Over three hours on Thursday, the once-allies engaged in a war of words via their own social media platforms, with Mr Trump's comments on Truth Social and Mr Musk's on X.
As their disagreement escalated, Mr Trump threatened to torch government contracts with Mr Musk's companies — most prominently, SpaceX.
"The easiest way to save money in our Budget, Billions and Billions of Dollars, is to terminate Elon's Governmental Subsidies and Contracts," Mr Trump wrote.
In return, Mr Musk invited the president to "go ahead, make my day".
The billionaire followed up 21 minutes later with a "really big bomb".
"@realDonaldTrump is in the Epstein files. That is the real reason they have not been made public," Mr Musk fired off on X.
"Have a nice day, DJT!" he added, referring to the president by his initials.
Mr Musk did not provide any evidence to substantiate the claim, but went on to share posts by others with little comment. The posts hinted at the past relationship between Mr Trump and convicted sex offender Jeffrey Epstein, who took his own life in prison after being arrested on a string of trafficking charges in 2019.
What are the Epstein files?
The term refers to a collection of evidence gathered by investigators working on the multiple criminal cases brought against Epstein and his associates.
While many court documents have been made public — including flight logs for Epstein's private jet — others remain sealed.
Some conspiracy theorists have suggested the FBI withheld the documents to cover up the guilt of Epstein's high-profile associates, though being named in the documents would not necessarily be proof of wrongdoing.
Since returning to the White House, the Trump administration has released some Epstein files and promised more would follow.
Attorney-General Pam Bondi said in May that the FBI was reviewing "tens of thousands" of documents related to Epstein.
She said materials would be released once necessary redactions had been made to protect victims and any ongoing investigations.
FBI deputy director Dan Bongino told Fox News on Wednesday — before Mr Musk made his accusations on X — the FBI would be releasing more Epstein-related documents in the coming weeks.
What are Trump's connections to Epstein?
It's known the pair were friends for almost two decades but there is no publicly available evidence suggesting Mr Trump engaged in illegal activity with Epstein.
The pair were photographed together at parties and Mr Trump's private golf club Mar-a-Lago during the 1990s and early 2000s.
Mr Trump flew on Epstein's private jet a number of times in the 1990s, mostly between Florida and New York, according to documents released as part of the trial of his associate Ghislaine Maxwell.
In 2002, the future president told New York Magazine that he'd "known Jeff for 15 years" and described the financier as a "terrific guy".
"He's a lot of fun to be with," Mr Trump said at the time.
"It is even said that he likes beautiful women as much as I do, and many of them are on the younger side."
Florida-based businessman George Houraney, who was a mutual connection of the pair, said he warned Mr Trump about Epstein "going after younger girls" ahead of a "calendar girl" competition held at Mar-a-Lago, according to the New York Times.
Mr Trump and Epstein ultimately had a falling out in 2004 over competition for Florida real estate.
The president reportedly told associates he later barred Mr Epstein from Mar-a-Lago for attempting to recruit a woman who worked at the club.
Mr Musk did not provide evidence of any criminal activity by the president, nor any new evidence about the nature of his relationship with Epstein.
Who was Epstein and what was he accused of?
The financier was a convicted sex offender accused of abusing and trafficking underage girls.
He pleaded guilty and was convicted in 2008 of procuring a child for prostitution and of soliciting a prostitute.
He was arrested in 2019 on sex trafficking charges, but died by suicide in his jail cell before he could face trial.
His associate, Oxford-educated heiress Ghislaine Maxwell, is currently serving 20 years in prison for helping him target and sexually abuse vulnerable young girls and women.
Epstein and Maxwell orbited numerous famous people, including politicians, celebrities and academics.
It's alleged he "lent" girls to his high-profile associates and kept blackmail material of their sexual exploits.
One of Epstein's alleged victims, Virginia Giuffre, publicly claimed Epstein and Maxwell forced her to have sex with Prince Andrew in 2001 — an allegation the Duke of York has consistently denied.
It is alleged many of Epstein's crimes were carried out on his private island, Little St James, in the Virgin Islands, which he travelled to and from by private jet.
The jet's published flight logs have drawn substantial public interest because they list the names of who Epstein travelled with and their destinations.
While flight logs have shown Mr Trump travelled on Epstein's jet, they do not mention a visit to Little St James.
