JPMorgan CEO Jamie Dimon has issued new remarks about bitcoin, dismissing the digital currency’s potential to survive in the long-term.

Speaking at the Fortune Global Forum, Dimon said people were wasting their time with digital currencies such as bitcoin.

He added:

“This is my personal opinion, there will be no real, non-controlled currency in the world. There is no government that’s going to put up with it for long … there will be no currency that gets around government controls.”

According to Dimon, bitcoin’s underlying blockchain technology has a brighter future: “The technology will be used, it may even be used to transport currency but it will be US dollars.”

Dimon’s latest comments come after he spoke about both bitcoin and blockchain technology during Barclays’ Global Financial Services Conference held in September.

Although cautious, the bitcoin skeptic said that JPMorgan – which recently partnered with distributed ledger startup R3CEV – was optimistic about the potential uses of blockchain technology.

In April this year, Dimon said his bank could learn from disruptive payment systems such as bitcoin in his annual letter to JPMorgan shareholders:

“You all have read about bitcoin, merchants building their own networks, PayPal and PayPal look-alikes. Payments are a critical business for us – and we are quite good at it. But there is much for us to learn in terms of real-time systems, better encryption techniques and a reduction of costs and ‘pain points’ for customers.”

Dimon’s comments on blockchain technology come amid increasing interest from banks and mainstream finance figures such as Blythe Masters, who famously left JPMorgan to join Digital Assets Holdings as CEO in March this year.