Washington, June 6 : US President Donald Trump has said that the "easiest way" for the government to save money would be to "terminate" contracts and subsidies going to billionaire and former adviser Elon Musk, amid an escalating public war of words between the Commander-in-Chief and the world's wealthiest man.

"The easiest way to save money in our Budget, Billions and Billions of Dollars, is to terminate Elon's Governmental Subsidies and Contracts," Trump wrote on his own social media platform Truth Social.

"I was always surprised that Biden didn't do it!" the US President said.

Trump's threat came after Musk accused the US President of "ingratitude" and said he would have lost the election without him, after the billionaire donated more than $250 million to help elect him last year.

Minutes earlier, Trump wrote that he had asked Musk to leave the White House, and claimed the Tesla CEO "just went CRAZY!"

"Elon was 'wearing thin,' I asked him to leave, 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," the President said. (There has never been a federal mandate that prohibited Americans from buying gasoline-powered cars.)

Trump insinuated in an Oval Office press conference on Thursday that the Tesla CEO opposes his "One Big Beautiful Bill Act," which Musk has been ranting about all week, because he is "upset" the electric vehicle incentive was removed, adding that he is not sure he will remain friends with Musk and alleging Musk "knew the inner workings of the bill".

Musk didn't reject the accusation about the EV tax credits in a tweet responding to Trump, writing it was "very unfair!!" that oil and gas subsidies were left in the bill, adding in a subsequent tweet "this bill was never shown to me even once and was passed in the dead of night so fast that almost no one in Congress could even read it!"

The breakup between the President of the US and the world's richest man is unfurling much like their relationship started ' rapidly, intensely and very publicly.

As President Donald Trump sat in the Oval Office on Thursday with Germany's leader, he lamented his soured relationship with Elon Musk, his adviser-turned-social media antagonist.

Trump said he was "very disappointed" with Musk after the billionaire and former Trump backer lambasted the President's signature bill of tax cuts and spending plans.

"Whatever," Musk wrote on his social media platform while responding to Trump in real time.

Politicians and their donor patrons rarely see eye to eye. But the magnitude of Musk's support for Trump, spending at least $250 million backing his campaign, and the scope of free reign the President gave him to slash and delve into the government with the Department of Government Efficiency is eclipsed only by the speed of their falling out.

Musk announced his support for Trump shortly after the then-candidate was nearly assassinated on stage at a Butler, Pennsylvania, rally last July.

News of Musk's political action committee in support of Trump's election came days later.

Musk soon became a close adviser and frequent companion, memorably leaping in the air behind Trump on stage at a rally in October. Once Trump was elected, the tech billionaire stood behind him as he took the oath of office, flew with him on Air Force One for weekend stays at Trump's Mar-a-Lago club in Palm Beach, Florida, slept in the White House's Lincoln Bedroom at the President's invitation and joined his Cabinet meetings wearing a MAGA hat (sometimes more than one).

"I'll be honest, I think he missed the place," Trump said on Thursday.

"He got out there, and all of a sudden he wasn't in this beautiful Oval Office."

Musk bid farewell to Trump last week in a subdued news conference in the Oval Office, where he sported a black eye that he said came from his young son but that seemed to be a metaphor for his messy time in government service.

Trump, who rarely misses an opportunity to zing his critics on appearance, brought it up on Thursday.

"I said, 'Do you want a little makeup? We'll get you a little makeup.' Which is interesting," Trump said.

The US President's comments came as Musk has stewed for days on social media about Trump's "Big Beautiful Bill," warning that it will increase the federal deficit. Musk has called the bill a "disgusting abomination".

"He hasn't said bad about me personally, but I'm sure that will be next," Trump said on Thursday in the Oval Office.

"But I'm very disappointed in Elon. I've helped Elon a lot."

"Look, Elon and I had a great relationship. I don't know if we will anymore," Trump said.

The President said some people who leave his administration "miss it so badly" and 'actually become hostile".

"It's sort of Trump derangement syndrome, I guess they call it," he said.

He brushed aside the billionaire's efforts to get him elected last year, including a $1 million-a-day voter sweepstakes in Pennsylvania. The surge of cash Musk showed he was willing to spend seemed to set him up as a highly coveted ally for Republicans going forward, but his split with Trump, the party's leader, raises questions about whether they or any others will see such a campaign windfall in the future.

Trump said Musk, the CEO and founder of Tesla, "only developed a problem' with the bill because it rolls back tax credits for electric vehicles.

"False," Musk fired back on his social media platform as the President continued speaking.

"This bill was never shown to me even once and was passed in the dead of night so fast that almost no one in Congress could even read it!"

In another post, he said Trump could keep the spending cuts but "ditch the MOUNTAIN of DISGUSTING PORK in the bill".

The bill would unleash trillions of dollars in tax cuts and slash spending but also spike deficits by $2.4 trillion over a decade and leave nearly 10.9 million more people without health insurance, according to an analysis by the Congressional Budget Office, which for decades has served as the official scorekeeper of legislation in Congress.

Besides Musk being "disturbed" by the electric vehicle tax credits, Trump said another point of contention was Musk's promotion of Jared Isaacman to run NASA.

Trump withdrew Isaacman's nomination over the weekend, days after Musk left his government role.

"I didn't think it was appropriate," Trump said, calling Isaacman "totally a Democrat".

Musk, reverting to his main form of political activity before he joined forces with Trump, continued slinging his responses on social media.

He shared some posts Trump made over a decade ago criticising Republicans for their spending, musings made when he, too, was just a billionaire lobbing his thoughts on social media.

/IANS