U.S. President Donald Trump lashed out against Elon Musk after he formed a new political party, calling the move “ridiculous,” and saying the tech billionaire had gone “completely off the rails”, writes CNBC

“I am saddened to watch Elon Musk go completely ‘off the rails,’ essentially becoming a TRAIN WRECK over the past five weeks”, Trump said in a post on Truth Social late Sunday stateside. “The one thing Third Parties are good for is the creation of complete and total disruption and chaos”.

Musk said in a post on X Saturday that he had set up the “American Party” to compete against the Republican and Democratic parties. The billionaire had teased for weeks the idea of a new political party, taking on Trump over the tax and spending plans that he said would bankrupt the economy.

“By a factor of 2 to 1, you want a new political party and you shall have it!” Musk wrote, “Today, the America Party is formed to give you back your freedom”.

Disagreement over the spending bill had led to a dramatic falling out between Trump and Musk, souring the bromance which saw Musk spend millions of dollars sponsoring Trump’s re-election bid and the president appoint Musk to lead the Department of Government Efficiency, known as DOGE, tasked with identifying areas to cut federal spending.

“I think it’s ridiculous to start a third party. We have a tremendous success with the Republican Party. The Democrats have lost their way, but it’s always been a two-party system, and I think starting a third party just adds to confusion,” Trump said Sunday, Reuters reported, a day after Musk’s announcement.

Trump also took aim at Musk’s push for an “Electric Vehicle Mandate” in the Sunday post, saying it would have “forced everyone to buy an Electric Car in a short period of time”. The president’s tax and spending cut bill, which was signed into law on July 4, put an end to tax credits for buyers of electric vehicles.