Bitcoin soared above $30,000 after Elon Musk said Tesla will likely resume accepting it as payment for its electric cars.

After his comments, Bitcoin gained 6% at $31,952 and Ethereum rose 10.6% at $179, according to data from Coindesk.

The electric car maker said in May that it would no longer accept cryptocurrency, citing concerns about the environmental impact of bitcoin mining that uses huge amounts of electricity. The move came less than two months after the company began accepting the world's largest digital currency as a payment method.

The answer is likely that Tesla will resume accepting Bitcoin,' Musk said Wednesday at the B Word Cryptocurrency Conference.

He also said he was investigating the use of fossil fuels in bitcoin mining, emphasizing that he wanted more scrutiny to confirm that the percentage of renewable energy use was likely 50% or higher, and that there is a trend towards increasing this percentage, and if that is the case, Tesla will resume accepting Bitcoin.

Some Tesla investors and environmental experts have attacked the company's decision earlier this year to start accepting Bitcoin as payment. The dispute highlighted the paradox of buying eco-friendly electric cars using an energy-intensive cryptocurrency.

Musk has also been criticized for using his popularity and status as one of the world's richest people to prop up cryptocurrencies.

In his appearance at the B Word conference, Musk said that, along with bitcoin owned by Tesla and his company SpaceX, he personally held cryptocurrency and other currencies such as Ethereum and Dogecoin.

He also touched on allegations that he helped artificially increase the price of cryptocurrencies before selling them, saying: I might invest, but I'm not giving up my holding. By raising the price and selling.. I would love to see Bitcoin succeed.

Other speakers at the B Word conference include Twitter CEO Jack Dorsey and ARK Investment Management's Cathy Wood.