The U.S. government has moved to block approximately $344 million in cryptocurrency believed to be linked to Iran, intensifying financial measures against Tehran even as the outlook for diplomatic progress remains unclear, CNN reported.

Officials at the Treasury Department said the action focused on several digital wallets as part of a wider effort to disrupt funding streams connected to Iran.

Authorities pointed to blockchain tracking that identified transactions tied to Iranian exchanges, as well as accounts associated with the country’s central bank.

The asset freeze was executed with the cooperation of Tether, which said it took action after being provided with intelligence from U.S. agencies indicating suspected illicit activity.

Analysts noted that while the move is notable, it is unlikely to have a major impact on Iran’s overall financial standing, as the country has repeatedly adjusted to sanctions and has increasingly turned to cryptocurrency as a way to work around restrictions.