The ties between United States President Donald Trump and billionaire Elon Musk have seen highs and lows throughout the years, writes Al Jazeera.

"But it all came crashing down on Thursday after months of what appeared to be an unshakable alliance in the White House.

A disagreement over Trump`s massive tax bill has escalated over the past few days, with Musk going so far as to suggest that the US president should be impeached.

In a series of social media posts, Musk launched personal attacks against Trump, culminating in a claim, made without evidence, that Trump is in the "Epstein files".

Those documents relate to the late sex offender Jeffrey Epstein and include travel logs and guest lists related to him and his associates. Part of the Epstein files remain secret, sparking curiosity and conspiracy theories about who might be mentioned.

Trump, meanwhile, responded with a social media fusillade of his own. He claimed he asked Musk to leave his White House role and suggested cutting the government subsidies and contracts awarded to the billionaire`s companies.

So how did the partnership between Musk and Trump collapse? And what may come next for the two men often described as the world`s richest and the world`s most powerful, respectively?"