Donald Trump has taken troll-in-chief Elon Musk down a peg in a withering statement issued as the world's richest man extends his tendrils through the US federal government.

Musk, 53, was enlisted by the 47th President to run the so-called Department of Government Efficiency (DOGE), an outside advisory body tasked with finding significant federal financial cuts. The centibillionaire, now a "special government employee" thanks to his new posting, has wasted no time getting stuck into the job, and his teams have gained access to several vital databases holding sensitive financial data.

While he has touted the importance of DOGE's mission on his bought-and-paid-for social media platform X, formerly Twitter, Mr Trump took his "First Buddy" down a peg in a recent media address. The President reminded the Tesla chief in a tightly worded statement that he is still beholden to the White House.

Speaking to the press earlier today while signing another round of executive orders, the President said Musk cannot take decisions without his administration's approval. He added the unelected billionaire would not receive approval to undertake actions "where not appropriate".

He said: "Elon can’t do and won’t do anything without our approval. And we’ll give him the approval where appropriate. Where not appropriate, we won’t." While Mr Trump has signalled he will keep Musk reined in, he and his DOGE employees have received everything they have asked for since the President took office on January 20.

Representatives for the organisation were allowed access to the internal federal payment system responsible for dispersing trillions of dollars a year last week. The greenlight came from Treasury Secretary Scott Bessent without pushback, and following massive outcry from existing government workers - many of whom have now left the department.

The move means DOGE operatives can now access a system responsible for Social Security and Medicare benefit payments, and, crucially, contracting payments made to outside firms. DOGE doesn't plan to stop there, as Musk and his allies are reportedly advocating for Treasury payment positions to be taken by Trump appointees.

Critics have raised the alarm over the prospect, claiming the President and his allies wish to restrict funding to their ideological rivals. Nathan Tankus, the research director of the Modern Money Network, told the Rolling Stone that Trump allies have entered the spending debate with a "very specific agenda".

He said: "This is not the attitude of people who are simply trying to make the payment system more ‘efficient'. They have a very clear and specific agenda, which involves unilaterally cutting spending, particularly spending they perceive to be going to their ideological foes.”