Trump says any country doing business with Iran will be hit with a 25% tariff

• President Donald Trump said he's imposing a 25% tariff against countries that "do business" with Iran.
• Details about how the tariff would be implemented were not immediately clear.
• Iran is currently experiencing mass protests against its government.

President Donald Trump said Monday that he'll impose a tariff of 25% on any country that does business with Iran.

"Effective immediately, any Country doing business with the Islamic Republic of Iran will pay a Tariff of 25% on any and all business being done with the United States of America," Trump said in a post on Truth Social.

It's unclear how the tariff will be implemented or which countries could be affected. The White House did not provide additional information when reached by Business Insider.

According to the World Bank, China and the United Arab Emirates are Iran's major trading partners.

The Trump administration has been trying to reach a trade deal with China after both countries backed down from a tariff war in 2025. According to China's Ministry of Foreign Affairs, the trade volume between China and Iran reached $13.37 billion in 2024, with China exporting $8.93 billion worth of goods to Iran and importing around $4.44 billion from the country. More recent data from the Observatory of Economic Complexity shows that China exported $456 million and imported $208 million from Iran in October 2025.

Trump's targeting of Iran comes as the country is experiencing mass protests against its government. Iran's crackdown on protesters has left hundreds dead and thousands arrested, the Human Rights Activists News Agency said.

Trump has expressed support for the protesters and threatened the possibility of US involvement.

"Iran is looking at FREEDOM, perhaps like never before," Trump wrote on Truth Social on Saturday. "The USA stands ready to help!!!"

Trump's announcement also comes as the Supreme Court is expected to rule this week on the legality of the tariffs his administration has imposed under the International Emergency Economic Powers Act, a 1970s-era law typically used by the President to impose sanctions.

Scott Bessent, Secretary of the Treasury, said in a petition to SCOTUS that the federal government could be on the hook to refund $1 trillion in tariffs to American businesses should the duties be ruled unconstitutional.

Trump also wrote in a post on Truth Social on Monday morning that "if the Supreme Court rules against the United States of America on this National Security bonanza, WE'RE SCREWED."