Crypto exchange Coinbase is preparing for a lengthy court battle with the Securities and Exchange Commission, or SEC, following a warning of potential violations of securities law, according to the company’s CEO.

Last month, the SEC issued a Wells notice to Coinbase, marking a potential step prior to the regulator issuing charges.

In a Tuesday interview with CNBC, Coinbase CEO Brian Armstrong called the notice “unfortunate” and said that the company has not received any specific feedback from the SEC on the issues involved.