"I don't think crypto's a fad. I don't think it's going to go away. I don't know what the value of Bitcoin should or shouldn't be. These things aren't going away."

Russian President Vladimir Putin further rattled American financial officials after hinting that while he considers cryptocurrency "crude and under-developed," it could "some day" be used instead of the US dollar to trade with.

The Russian president discussed potential use cases of cryptocurrencies in a Thursday CNBC interview following a plenary session of the ??Russian Energy Week forum.

"I believe that it has value," Putin told CNBC at the Russian Energy Week event in Moscow on Wednesday, when asked whether bitcoin or cryptocurrencies can be used in place of the US dollar.

"But I don't believe it can be used in the oil trade."