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.