The U.S. Treasury's Financial Crimes Enforcement Network (FinCEN) has issued an order cutting MEXC Global, one of the world's 20 largest crypto exchanges, off from the U.S. financial system, accusing the platform of facilitating at least $16 billion in illicit transactions tied to sanctions evasion and cybercrime.

In the order issued Friday, Treasury said MEXC served as a major conduit for funds connected to Iran, North Korea and Russia. The action, part of a broader effort dubbed Operation Economic Outcast, bars U.S. financial institutions from processing any funds transfers to or from the exchange. It takes effect 30 days after publication in the Federal Register, meaning U.S. financial institutions will not be barred from handling the exchange's transfers until that date. The measure was announced in a Treasury press release.

"Financial institutions cannot have it both ways: Either you support the Iranian regime, or you have access to the U.S. financial system," Treasury Secretary Scott Bessent said in a statement, vowing to keep severing the regime's "economic lifelines" and its attempts to use digital assets to dodge sanctions.

Founded in 2018, MEXC processes more than $1 billion in daily transactions, holds around $5 billion in reserves, and offers more than 3,000 tokens, according to FinCEN. Between May 2021 and May 2026, the agency said, the platform moved at least $16 billion connected to illicit activity, including nearly $1.5 billion tied to Russian sanctions evasion, with $232 million in direct transactions with sanctioned entities. FinCEN named MEXC a "primary money laundering concern" in connection with Russian illicit finance.

Despite publicly claiming to maintain anti-money-laundering controls and barring users in jurisdictions such as Iran and North Korea, MEXC's compliance was riddled with "severe deficiencies," FinCEN said. The exchange was still transacting with sanctioned Russian exchange Garantex and its successor Grinex as recently as June 2026—more than four years after Garantex was first designated. It also processed roughly $200 million linked to the A7A5 stablecoin and about $22 million benefiting Iran's central bank and its Islamic Revolutionary Guard Corps (IRGC).

Those connections place MEXC squarely within a sprawling sanctions-evasion ecosystem that Treasury has been dismantling piece by piece. Last month, the department designated Russia's A7 Network a transnational criminal organization and proposed cutting its front companies off from U.S. finance, flagging more than $179 billion in transactions through its ruble-backed A7A5 token, much of it routed through Garantex and Grinex.

The same campaign has reached into Iran's crypto sector, where Treasury gained sweeping authority to sanction anyone operating in it and blacklisted the Iranian exchange Nobitex over its role in funneling crypto to the IRGC.

The order against MEXC relies on a provision of the Combating Russian Money Laundering Act rather than a standard sanctions designation—a route that runs through a "primary money laundering concern" finding, and one FinCEN has increasingly reached for to cut off crypto infrastructure that operates outside the correspondent banking system.