US President Donald Trump has threatened what he called an unprecedented economic campaign and isolation against Iran, as talks to end a conflict lasting more than five months remain deadlocked. In a Wednesday Truth Social post, Trump said Iran had failed to take an opportunity for a deal and warned of severe economic consequences for countries providing any form of support to Tehran through financial institutions, businesses, airports or government bodies.

Trump called for action against oil smuggling, barter arrangements, cash transfers, currency exchange centers, ship registration and front companies working for Iran. He described the planned effort as an “economic D-Day” and urged US allies to join efforts to confront and isolate Iran. Since April, his administration has pursued “Operation Economic Fury,” imposing broad measures on Iran’s oil, shipping and financial sectors, as well as a naval blockade on Iranian ports.

Iran’s government did not immediately comment, while Iranian media dismissed the announcement as insignificant and said Tehran had learned to evade sanctions. Analysts said possible secondary sanctions could target Chinese institutions serving independent refineries that buy Iranian oil, but warned such moves could provoke significant international reactions and complicate ongoing US-China trade talks.