The U.S. government ratcheted up pressure on Tehran , imposing sanctions on 35 entities and individuals in Iran 's shadow banking sector. It also threatened banks doing business with Chinese "teapot" refineries, accused of paying tolls for Strait of Hormuz passage. The Treasury Department's Office of Foreign Assets Control (OFAC) said designated individuals and firms facilitated the movement of tens of billions of dollars tied to sanctions evasion and Iran 's sponsorship of terrorism. OFAC separately warned banks against doing business with firms paying the Iranian government or Islamic Revolutionary Guard Corps for the strait passage, citing the significant sanctions risk. It singled out independent Chinese teapot refineries, mainly in Shandong province, given their role in importing and refining Iranian oil. Some had used the U.S. financial system for dollar transactions and to procure U.S. goods.…