US President-elect Donald Trump has picked Elon Musk for a role in government cost-cutting, as part of his drive to "dismantle" bureaucracy when he returns to the White House next year.

Tech billionaire Musk, who has called for huge spending cuts, has been picked alongside biotech investor Vivek Ramaswamy to lead a new "Department of Government Efficiency" (Doge). The acronym is a nod to Musk's favourite cryptocurrency, Dogecoin.

Trump said the pair would act in an advisory capacity, and that the Doge would not be an official government department.

On the same day, Trump named another political newcomer - Fox News host and military veteran Pete Hegseth - as his pick for defence secretary.

Musk threw millions behind Donald Trump's successful re-election bid, and was hotly tipped for a role in the administration that has so far rewarded loyalists. Trump himself outlined a plan for Musk in government cost-cutting on the campaign trail.

Ramaswamy ran as a Republican candidate for president earlier this year against Trump, before dropping out and endorsing him.

Since triumphing in last week's vote, Trump has been assembling his top team - with another of his one-time Republican rivals, Marco Rubio, reportedly in the frame to be his new secretary of state.

Trump looks likely to enjoy significant support for his legislative agenda in Congress. Republicans won the Senate and are closing in on control of the House.

What is the Doge?

It remains to be seen how the Doge will operate.

The organisation does not currently exist and, when created, it is not expected to be an official department. Such agencies have to be established through an act of Congress and typically employ thousands of staff.

In Tuesday night’s announcement, Trump acknowledged that it will "provide advice and guidance from outside of government". He said the initiative would help his administration "dismantle government bureaucracy, slash excess regulations, cut wasteful expenditures and restructure federal agencies".

He said Musk and Ramaswamy would work with the White House and Office of Management & Budget to tackle "massive waste and fraud" in $6.5tn (£5.1tn) of annual government spending.

Trump has likened the new initiative to the Manhattan Project, a top-secret World War Two programme to develop the first nuclear weapons.

The president-elect said Musk and Ramaswamy would complete their work no later than 4 July (American Independence Day) 2026.

The organisation's name refers to Musk's preferred cryptocurrency - which was itself jokingly in 2013 named after an internet meme. Dogecoin has soared in value over the past week.

The roles of Musk and Ramaswamy

In business, Musk has become known for his opposition to perceived government overregulation and his approach to cost-cutting - most notably after he took over Twitter, which he rebranded X and laid off thousands of staff.

Musk, who also founded SpaceX and Tesla, recently called for at least $2tn in cuts to US federal spending, nearly a third of the government's budget, without offering specifics. He has also proposed eliminating hundreds of federal agencies, arguing that many of them have overlapping areas of responsibility.

In a press release from Trump's campaign, Musk said: “This will send shockwaves through the system, and anyone involved in government waste, which is a lot of people."

After the announcement, Musk posted on X: “Threat to democracy? Nope, threat to BUREAUCRACY!!!”

Ramaswamy reposted Trump's announcement on social media saying "we will not go gently". He also said he was withdrawing from consideration to fill incoming US Vice-President JD Vance’s soon-to-be-vacated Ohio Senate seat.

Last year, while running for president, Ramaswamy said he would fire more than 75% of the federal work force and close down several major agencies, including the Department of Education, the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Since Trump's election victory last week, Musk has reportedly spent every day with Trump at his estate in Palm Beach, Florida.

He also took part in a recent phone call Trump had with Ukrainian President Volodymyr Zelensky.

Flurry of appointments

Trump announced the appointments of Musk and Ramaswamy amid a flurry of press releases on Tuesday evening, which also saw several senior national security positions filled.

John Ratcliffe, slated to lead the CIA, previously served as Trump's director of national intelligence and oversaw US intelligence agencies. South Dakota Governor Kristi Noem was confirmed as Trump's nomination to serve as secretary of homeland security.

Meanwhile, some eyebrows were raised at the nomination of Fox News host Pete Hegseth to lead the Pentagon. A veteran of the Iraq war, he has limited experience of government but has been a vocal supporter of Trump's for several years.