Tesla will no longer accept bitcoin over climate concerns, says Musk

But on Thursday, it backtracked on its previous comments. 

"We are concerned about rapidly increasing use of fossil fuels for Bitcoin mining and transactions, especially coal, which has the worst emissions of any fuel," Mr Musk wrote.

"Cryptocurrency is a good idea… but this cannot come at great cost to the environment." 

He also said the electric carmaker would not sell any of its bitcoin, and intends to use it for transactions as soon as mining shifts to using more sustainable energy.

Tesla has suspended vehicle purchases using bitcoin due to climate change concerns, its CEO Elon Musk said in a tweet. 

Bitcoin fell by more than 10% after the tweet, while Tesla shares also dipped. 

Tesla's announcement in March that it would accept the cryptocurrency was met with an outcry from some environmentalists and investors.

The electric carmaker had in February revealed it had bought $1.5bn (£1bn) of the world's biggest digital currency.