U.S. Sen. Elizabeth Warren, D-Mass., is urging the Biden Administration to address Iran's foray into crypto mining as that country leverages lucrative bitcoin operations to circumvent international sanctions.

In the letter, sent on Wednesday to the Secretaries of the Treasury and Defense and National Security Advisor Jake Sullian, Warren argued Iran’s crypto operations pose a “direct threat to… national security,” The Hill reported. As a result, one of the Senate's most outspoken crypto critics requested that the administration outline Iran’s “reliance on crypto mining…. to earn revenue and bypass sanction” to mitigate the issue.

“Iran has raised millions of dollars through mining crypto—a steady revenue source that allows it to purchase imports, move funds domestically and …