Tether froze more than $344 million in USDT across two addresses Thursday in coordination with the U.S. authorities, the stablecoin issuer announced, in one of the largest compliance actions in the company’s history.

The freeze was executed after U.S. officials shared information related to suspected sanctions evasion, criminal networks, and other illicit activity, the crypto company said in a statement. The Treasury Department’s Office of Foreign Assets Control (OFAC) took part in the action, Decrypt reported.

While Tether did not identify the network involved, security firm PeckShield identified the blacklisted addresses as located on the Tron blockchain, holding approximately $213 million and $131 million respectively, according to Decrypt, which first reported the action. Tether did not immediately respond to the news outlet’s request to confirm the addresses.

“USDT is not a safe haven for illicit activity,” Tether Chief Executive Paolo Ardoino said in a statement. “When credible links to sanctioned entities or criminal networks are identified, we act immediately and decisively. Recent events have shown what happens when platforms fail to move quickly, enforcement breaks down, users are exposed, and trust erodes.”

Tether said the cooperation with law enforcement has become “a routine part” of its response to lawful requests from authorities in the U.S. and abroad, describing its model as coordinating directly with investigators during active cases, rather than reacting after funds have already moved. The company froze roughly $182 million across five Tron wallets in a separate action in January 2026, Decrypt noted. 

The freeze comes amid heightened scrutiny of stablecoin issuers’ compliance practices following a pair of high-profile crypto hacks attributed by investigators to North Korean actors: the $285 million Drift Protocol attack and the $292 million Kelp DAO exploit, Decrypt said.

Rival issuer Circle drew criticism for declining to freeze funds linked to the Drift Protocol hack without a law enforcement directive or court order, and a class action lawsuit has since been filed against the company in connection with the incident, according to the news outlet. Drift said last week it would abandon Circle’s USDC in favor of USDT as part of a Tether-backed recovery plan that includes $148 million in funding to compensate affected users, Decrypt reported.