“I am not a fan of bitcoin and other cryptocurrencies, which are not money, and whose value is highly volatile and based on thin air,” Mr Trump tweeted.
He added: “Unregulated crypto assets can facilitate unlawful behaviour, including drug trade and other illegal activity. Similarly, Facebook Libra’s ‘virtual currency’ will have little standing or dependability.”
Mr Trump said if Facebook and other companies “want to become a bank”, they must become subject to national and international banking regulations.
He signed off his Twitter rant with typically nationalistic rhetoric, stating: “We have only one real currency in the USA, and it is stronger than ever, both dependable and reliable. It is by far the most dominant currency anywhere in the world, and it will always stay that way. It is called the United States Dollar!”
Trump’s comments appeared to have no negative impact on the cryptocurrency market, with bitcoin actually gaining 1 per cent in value since the tweets were posted.
“The irony is that in tweeting about bitcoin, Trump has just given it the single best piece of publicity it has ever had,” Nicholas Gregory, founder of the blockchain firm CommerceBlock, told The Independent.
“I wouldn’t be surprised to see bitcoin rally on the back of it. The cryptocurrency industry will be rubbing its hands with glee.”
Brian Armstrong, the CEO of popular bitcoin exchange Coinbase, said Mr Trump’s tweets were an “achievement” for bitcoin.
“I dreamt about a sitting US president needing to respond to growing cryptocurrency usage years ago,” he wrote.
“’First they ignore you, then they laugh at you, then they fight you, then you win’, We just need to make it step 3 y’all.”
“This is a major mistake on your part and shows a complete lack of vision,” tweeted far right commentator Mike Cernovich.
Others pointed out that leaving behind the Gold Standard and measures like quantitative easing mean traditional currencies like the US dollar can also be created “out of thin air”.
One Twitter user noted: “Since the dollar is not backed by gold anymore and money is being printed out of thin air by the central banks, it really isn’t more real than bitcoin.”