President Trump threatened to impose a 25 percent tariff on countries doing business with Iran on Monday in response to a violence crackdown by Tehran on growing anti-government protests. 

“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. This Order is final and conclusive,” Trump said in a post on TruthSocial. 

Protests challenging Iran’s theocracy have gained traction in recent weeks as Iranian leadership forcefully tamps down on the demonstrations. Activists estimate that 538 people have died related to the protests, while 10,600 others have been detained, according to the U.S.-based Human Right Activists News Agency.

Trump told reporters on Sunday that Iran was starting to cross the red line in how the country’s leadership cracked down on the protests. However, Trump said that Iran reached out to him and that a meeting is being set up. 

White House press secretary Karoline Leavitt told reporters on Monday that potential air strikes and diplomacy were among the options Trump was considering. 

“I think one thing President Trump is very good at is always keeping all of his options on the table,” Leavitt said. “Airstrikes would be of the many, many options that are on the table for the commander-in-chief. Diplomacy is always the first option for the president. He told all of you last night that what you’re hearing from the Iranian regime is quite differently from the messages the administration has received privately.” 

“I think the president has an interest in exploring those messages. However with that said, the president has shown he’s unafraid to use military options if and when deemed necessary,” she continued. “Nobody knows that better than Iran.”