UK and US Tighten Sanctions on Iranian Oil Network

The United Kingdom on 21 August froze the assets of Iranian oil magnate Hossein Shamkhani and four affiliated companies operating in the shipping, petrochemical and financial sectors. London said the group formed part of a network that supports Tehran’s overseas activities, including operations in Ukraine and Israel, and posed a threat to UK and international security. The designations bar British individuals and businesses from dealing with the parties. Hours later the U.S. Treasury Department’s Office of Foreign Assets Control imposed its own sanctions on Greek national Antonios Margaritis, a network of companies he controls, and nearly a dozen vessels the agency said helped transport Iranian crude. The United States also blacklisted additional entities based in Hong Kong. Treasury said the measures aim to cut off revenue Iran uses to fund militant groups, expanding Washington’s campaign against Tehran’s so-called shadow fleet. The coordinated actions from London and Washington intensify economic pressure on Iran’s energy supply chain and signal closer alignment among Western allies in curbing Tehran’s oil revenues.