WASHINGTON—President Donald Trump on Monday warned countries against doing any business with Iran, promising that any such countries will pay a tariff on their business with the United States. “Effective immediately,” the president shared on Truth Social, “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,” he added. “Thank you for your attention to this matter!” Trump’s post comes as demonstrations throughout Iran challenging the cleric-controlled system rock the Iranian regime. Behnam Ben Taleblu, senior director of the Iran program at the Foundation for Defense of Democracies, told Morning Wire this week that the demonstrations are the most consequential challenge to the Iranian government’s legitimacy since the birth of the Islamic theocracy in 1979. “Iranians pushed past reform, Iranians pushed past the ballot box and found the street to be the best way to contest the state and make their case,” Taleblu explained, “not just to their fellow compatriots and citizens, but to the world that they seek wholesale political change – not evolution, not musical chairs at the top, not another fig leaf, not putting lipstick on a pig.” TEHRAN, IRAN – JANUARY 12: People join a pro-government rally on January 12, 2026, in Tehran, Iran. (Photo by Stringer/Getty Images) Iranian authorities have restricted citizen access to the internet for five days now as the protesters chant “Death to Khamenei,” referencing Iran’s Supreme Leader Ayatollah Ali Khamenei. Iranian security forces are responding to the unrest with violence: U.S.-based Human Rights Activists News Agency (HRANA) reports that 503 protesters in Iran have died. White House Press Secretary Karoline Leavitt said Monday that the president is ready to use military force against Iran if necessary. In June, the United States struck and obliterated Iran’s nuclear sites under Operation Midnight Hammer, destroying the country’s nuclear program for the time being. “I think one thing President Trump is very good at is always keeping all of his options on the table, and air strikes would be one of the many, many options that are on the table,” Leavitt shared during a gaggle with reporters outside the White House. “Diplomacy is always the first option” for the president, she noted. “He told all of you last night that what you’re hearing publicly from the Iranian regime is quite different from the messages the administration is receiving privately,” Leavitt said. “The president has shown that he is unafraid to use military options if and when he deems necessary, and nobody knows that better than Iran.” And the president himself said on Sunday that Iranian leaders called him to negotiate, saying: “I think they are tired of being beat up by the United States.” The president shared that a meeting is being set up, but noted that he may “have to act” before that meeting occurs “because of what’s happening.” He also told reporters that he and his military are “very seriously” considering their options given the violence in Iran: “There seems to be some people killed that aren’t supposed to be killed. These are violent — if you call them leaders, I don’t know if they are leaders — they rule through violence.” “We’ll make a determination,” the president said.