do not join the economic war waged by the United States," said Mohsen Rezai, the head of Iran's supreme national security council, on Iranian television."Any country participating in the imposition of economic restrictions against us is considered an enemy."Data from the US treasury department's Office of Foreign Assets Control (OFAC) shows the agency has imposed sanctions on more than 1,000 people, vessels and aircraft since Trump began his second term.Recent measures have targeted Iran's shadow oil fleet; shipping insurers; entities and people enabling Iran's acquisition of weapons; and digital exchanges, freezing an estimated US$500 billion ($697 billion) in Iran-linked cryptocurrency.Oil shipments are at a virtual standstill in the Strait of Hormuz, with Tehran threatening to strike any unauthorised oil tankers that try to transit the vital waterway.Experts say the Trump administration can try the following options to put more pressure on Iran:Chinese independent refineries known as "teapots" account for a quarter of Chinese refinery capacity They worry that China could curtail exports of critical minerals that are essential to advanced technology production at a time when the US and Western allies are still trying to develop their own supplies.The United States could continue targeting Iranian individuals and entities, as well as others in China and the Gulf, that are helping Tehran evade sanctions to collect revenues for its war effort.The US treasury department recently issued sanctions against firms that are springing up to facilitate Iran's trading of oil revenue for imports