WASHINGTON: US President Donald Trump said on Thursday he was `very disappointed` by Elon Musk`s criticism of his policy mega-bill, adding he didn`t know if his friendship with his billionaire former advisor would survive.

In an extraordinary rant in the Oval Office as visiting German Chancellor Friedrich Merz sat mutely beside him, Trump unloaded on SpaceX and Tesla boss Musk in his first comment s on the issue.

`Look, Elon and I had a great relationship. I don`t know if we will anymore. I was surprised, Trump told reporters in the Oval Office after former advisor Musk slammed the bill as an `abomination`.

`I`m very disappointed,because Elon knew the inner workings of this bill better than almost anybody sitting here... All of a sudden, he had a problem,` Trump added.

Musk hit back minutes later on his X social network, saying the78-year-old president`s claims he had advance sight of the bill were `false.` `Whatever,` he added above a video of Trump saying Musk was upset about the loss of subsidies for electric vehicles.

Elon Musk ratcheted up his public spat with Donald Trump, saying the US president would have lost the election without his support.

`Without me, Trump would have lost the election,` Musk said on X. `Such ingratitude.

The latest clash comes less than a week since Trump held a grand Oval Office farewell for Musk as he wrapped up his time leading the cost-cutting Department of Government Efficiency (DOGE).

Musk stunned reporters at the time by turning up with a black eye that he said was caused by his son.

`You saw a man who was very happy when he stood behind the Oval desk, and even with the black eye. I said, you want a little makeup? We`ll get you a little makeup,` Trump said. `But he said, `No, I don`t think so,` which is interesting and verynice.

He wants to be who he is.

Trump said he could understand why Musk was upset with some steps he had taken, including withdrawing a nominee to leadthe Nasa space agency whom the techtycoonhadbacked.

The US president`s `big, beautiful bill` on tax and spending the centerpiece of his domestic agenda could define his second term and make or break Republican prospects in the 2026 midterm elections.

Musk however called it a `disgusting abomination` on Tuesday.

A day later, the magnate called for Republicans to `kill the bill, and for an alternative plan that `doesn`t massively grow the deficit.

Cracks in the relationship between President Donald Trump and Tesla CEO Elon Musk, his selfproclaimed `First Buddy`, are scaring Tesla shareholders as the two fired salvos at each other in increasingly heated rhetoric on Thursday.

Shares fell more than 8pc on a day otherwise devoid of news for the electric automaker, as traders dumped the stock in heavy trading after Musk stepped up his criticism of the president`s tax bill.

Trump fired back, alleging Musk was upset because the bill takes away tax benefits for electric vehicle purchases, while investors feared their souring relationship could hurt Musk`s sprawling business empire.-Agencies