The wealthy tech entrepreneur will take on a newly created role advising the Trump administration on cryptocurrency and artificial intelligence.

"David will guide policy for the Administration in Artificial Intelligence and Cryptocurrency, two areas critical to the future of American competitiveness," Trump said in a social media post.

"He will safeguard Free Speech online and steer us away from Big Tech bias and censorship."

Sacks will also lead a presidential council of advisors on science and technology, according to Trump.

The entrepreneur, whose wealth has been estimated in the billions of dollars, is considered part of a so-called "PayPal Mafia" cadre of influential tech entrepreneurs that includes Elon Musk and Peter Thiel.

The group was part of that company's founding era and members have thrown their clout behind conservative political policies and candidates.

Sacks backed J.D. Vance as Trump's running mate in the recent US presidential election, hosting Vance on his podcast in the process.

After PayPal was bought by eBay in 2002, Sacks went on to help create other tech firms including Yammer, which was bought by Microsoft.

Sacks, who like Musk was born in South Africa, also took to investing in startups.

Bitcoin breached $100,000 on Thursday before dipping back below the symbolically important level.

The digital asset has now soared more than 50 percent since the election of Trump, who has vowed to make the United States the "bitcoin and cryptocurrency capital of the world."

The historic level was broken after Trump picked crypto proponent Paul Atkins to take over as chair of the Securities and Exchange Commission, the markets regulator.

Atkins "is unlikely to be as anti-crypto as his predecessor Gary Gensler," said Kathleen Brooks, research director at the XTB trading platform.

"Politics is driving bitcoin. We doubt that the rally will stop here," she added.

- Musk meetings -

Musk met with US lawmakers Thursday to discuss his plans for overseeing radical government spending cuts under the incoming administration.

Trump rewarded the Tesla, X and SpaceX chief for his support during the White House campaign by naming him head of the newly created Department of Government Efficiency, along with another wealthy ally, Vivek Ramaswamy.

Although the office, dubbed DOGE, has a purely advisory role, Musk's star power and intense influence in Trump's inner circle bring political clout.

During Trump's election campaign, Musk vowed to reduce federal spending by $2 trillion.

This would represent cutting total US spending by a third, almost certainly meaning devastation of social support programs -- something that has never garnered strong political backing.

Musk's new role raises the question of potential conflicts of interest, since he could be issuing policy recommendations that impact directly on his own business empire.

Underlining the close connection to DOGE, Musk's favorite cryptocurrency is called Dogecoin.