Banks have "little or no appetite" to get involved with bitcoin and cryptocurrencies due to fears of a bubble and illicit activity associated with it, the chief executive of Credit Suisse said Thursday.

"I think most banks in the current state of regulation have little or no appetite to get involved in a currency which has such anti-money laundering challenges," Tidjane Thiam said at a news conference, according to Reuters.

The banking executive's comments came as the digital currency surpassed $7,000 for the first time.

Thiam added that investors were only buying into the digital asset "to make money," and described it as "the very definition of speculation and the very definition of a bubble."

The chief financial officer of ING also weighed in on cryptocurrency worries Thursday, saying that, although digital assets are an effective means of exchange, the bank was not advising clients to in invest in them.