The U.S. Treasury Department said it had severed MEXC Global’s ties to the United States over allegations involving $16 billion in transactions linked to Iran, North Korea and Russia. On Friday, the Treasury’s Financial Crimes Enforcement Network issued an order against the cryptocurrency exchange and designated it as a money-laundering risk. The Treasury alleged that despite MEXC Global’s claims that it had safeguards in place and its pledge to block users from countries including Iran and North Korea, its anti-money-laundering controls had serious deficiencies.