SummaryThe U.S. Treasury added four wallets linked to Iran’s central bank to its sanctions list, leading Tether to freeze $131 million in USDT.The freeze targets TRON-based addresses that previously held over $165 million, preventing those specific funds from being transferred or redeemed.This action brings the total amount of blocked USDT linked to Iran's central bank to roughly $475 million.The U.S. added four crypto wallets linked to the Central Bank of Iran to its sanctions list after a ceasefire agreement between the two countries broke down and air and drone strikes resumed.The four Tron-blockchain wallets had received more than $165 million in stablecoins, according to Chainalysis. Tether blocked $131 million in USDT held by the accounts, though some of the funds had moved before the freeze.Sanctioning the wallets gives exchanges, custodians and compliance firms a clear set of addresses to screen for. Iran’s central bank has accumulated at least $507 million in USDT, according to Elliptic, using the token to support the rial. The U.S. Treasury Department’s Office of Foreign Assets Control (OFAC) has said its published wallet lists are not exhaustive, meaning other addresses controlled by the bank may still qualify as blocked property.Tuesday’s OFAC update expands on an existing designation rather than imposing new sanctions. The Central Bank of Iran has been blocked under U.S. counterterrorism authorization since 2019 over its support for the Islamic Revolutionary Guard Corps-Qods Force and Hezbollah.The action follows OFAC’s June sanctions on Nobitex and other Iranian exchanges accused of helping the central bank move in and out of stablecoins.In April, Tether froze $344 million in USDT linked to the bank, bringing the total blocked across both actions to roughly $475 million.Chainalysis said the four addresses received funds from an institutional liquidity provider and an Asia-based payment processor,The frozen tokens remain visible onchain, but the addresses can no longer transfer or redeem them. The freeze, however, does not amount to a seizure as the funds remain under the control of the wallets belonging to Iran’s central bank.