Trump says any country doing business with Iran will face 25 percent tariff 

United States President Donald Trump has said that countries that engage in trade with Iran will face a 25 percent tariff on any business done with the US.

Trump announced the decision in a social media post on Monday, stating that it was “final and conclusive”, but offering few additional details.

“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 his website, Truth Social.

It is not clear which countries might be affected, but major economies such as Russia, China, Brazil and Turkiye all trade with Iran, which has been roiled by widespread antigovernment protests and riots over the past week.

Iraq and the United Arab Emirates are also important trading partners, according to the database Trading Economics.

In recent weeks, Trump has ratcheted up pressure on Tehran and threatened further military strikes on the country, should it fail to abide by US demands to wind down its nuclear and military programmes.

“Now, I hear that Iran is trying to build up again, and if they are, we’re going to have to knock them down,” Trump told reporters in December. “We’ll knock them down. We’ll knock the hell out of them. But, hopefully, that’s not happening.”

In June, the US bombed three Iranian nuclear facilities as part of a 12-day war initiated by Israel. US strikes on Iran likely constitute a violation of international law, according to legal experts.

“Air strikes would be one of the many, many options that are on the table,” White House Press Secretary Karoline Leavitt said on Monday, adding that Trump remains interested in diplomacy, if possible.

Trump has also criticised Iran’s harsh crackdown on antigovernment protesters and warned that any violence could also lead to a US strike.

In a January 2 post on Truth Social, the US president indicated he would consider taking military action should protesters be killed.

“If Iran shots [sic] and violently kills peaceful protesters, which is their custom, the United States of America will come to their rescue. We are locked and loaded and ready to go,” he wrote.

The threat came one day before the US launched a military attack in Venezuela, which resulted in the abduction of President Nicolas Maduro and his wife, Cilia Flores.

Still, human rights groups have warned that hundreds of people have been killed in Iran, but an internet blackout in the country has restricted the flow of information.