United States President Donald Trump has announced the imposition of a 25 per cent tariff on any country that maintains commercial relations with Iran.

Trump made the declaration on Monday via his Truth Social platform, stating that the policy takes effect immediately and is non-negotiable.

“Any country doing business with the Islamic Republic of Iran will pay a tariff of 25 per cent on any and all business being conducted with the United States of America,” the president said.

However, Trump did not clarify how the policy would be implemented or define the threshold of economic engagement that would amount to “doing business” with Iran.

The announcement comes amid escalating anti-government protests across Iran following a sharp depreciation of the national currency, the rial. The protests reportedly began on December 28 in Tehran, where shop owners demonstrated against worsening economic conditions.

The unrest has since spread nationwide, with demonstrators expressing anger over inflation, unemployment, and political repression.

According to the Iranian Human Rights Activists News Agency, protests have been recorded in at least 186 cities and towns across all provinces in the country.

Human rights organisations claim that security forces have responded with excessive force. Iran Human Rights, a Norway-based group, said no fewer than 648 protesters have been killed since the demonstrations began, while thousands have sustained injuries.

Eyewitnesses told international media that security personnel fired live ammunition directly at demonstrators. Authorities have also imposed a digital blackout, restricting internet access and limiting independent verification of events.

Iran’s economy has remained under severe strain due to prolonged US sanctions linked to its nuclear programme, as well as allegations of corruption and poor governance.

The rial has fallen to record lows in recent months, while inflation has surged, driving up the cost of basic food items. Food imports account for about one-third of Iran’s total imports, raising concerns that further trade restrictions could worsen shortages.

Trump has previously warned that Washington is considering “very strong options” in response to the violence and said the United States is prepared to support Iranian protesters if the government continues its crackdown.