WASHINGTON, March 20 (Reuters) – The U.S. on Thursday issued new Iran-related sanctions, targeting entities including for the first time a Chinese “teapot”, or independent refinery, and vessels that supplied crude oil to such processing plants.

It was Washington’s fourth round of sanctions on Iran’s oil sales since President Donald Trump said in February he was re-imposing a “maximum pressure” campaign including efforts to drive down the country’s exports to zero. Trump aims to stop Tehran from obtaining a nuclear weapon and funding militant groups.