United States President Donald Trump called Tesla CEO Elon Musk “CRAZY” on Thursday and threatened to cut his companies’ government contracts amid a feud over a major tax bill.

“Go ahead, make my day,” Musk promptly responded.

Besides heading electric vehicle maker Tesla, Elon Musk also leads SpaceX, xAI, The Boring Company, Neuralink, and the social media platform X.

Tesla’s stock, already falling, plunged further following Trump’s recent remarks.

The dramatic fallout between the world’s richest man and the U.S. president comes less than a week after they exchanged compliments at an Oval Office send-off honoring Musk’s leadership of the Department of Government Efficiency.

On Thursday afternoon, Trump posted on Truth Social that Musk was “wearing thin” by the end of his time as a “special government employee.”

“I asked him to leave,” Trump claimed.

The harsh remark came after Musk criticized the president during a growing dispute triggered by the billionaire’s outspoken opposition to Trump’s large budget bill.

Earlier on Thursday in the Oval Office, Trump said Musk was “upset” over the bill’s cuts to electric vehicle tax credits.

“I took away his EV Mandate that forced everyone to buy Electric Cars that nobody else wanted (that he knew for months I was going to do!), and he just went CRAZY!” Trump wrote in the social media post.

Musk has strongly criticized the bill, arguing that it will add trillions to the nation’s deficit. He is actively urging Senate Republicans to “kill the bill,” which includes a large part of Trump’s domestic agenda.

In a second Truth Social post, the president wrote, “The easiest way to save billions and billions of dollars in our budget is to terminate Elon’s government subsidies and contracts. I was always surprised that Biden didn’t do it!”