U.S. President Donald Trump takes questions from reporters, as he attends a meeting with oil industry executives, at the White House in Washington, D.C., U.S., Jan. 9, 2026.
Kevin Lamarque | Reuters
President Donald Trump on Monday said any country doing business with Iran will face a 25% tariff “on any and all business being done with the United States of America.”
That new tariff on imports from Iran’s trading partners is “effective immediately,” Trump said in a Truth Social post.
“This Order is final and conclusive. Thank you for your attention to this matter!” he wrote.
Further details about the tariff announcement were not immediately clear. A White House official declined to answer CNBC’s questions about the president’s social media post.
The apparent effort by Trump to economically isolate Iran comes as the oil-rich Middle Eastern country struggles to suppress an ongoing swell of massive anti-government protests.
Dozens of those protesters have reportedly been killed in recent weeks; Trump has threatened to take military action against Iran if the killings continue.
The president has also explicitly encouraged the demonstrations against the Iranian regime. “Iran is looking at FREEDOM, perhaps like never before. The USA stands ready to help!!!” he wrote on social media on Saturday.
The announcement of new tariffs on Iran’s business partners also comes ahead of a much-anticipated Supreme Court ruling on whether many of Trump’s most expansive tariffs are legal.
Those tariffs — including his controversial “reciprocal” duties from early April and others related to purported fentanyl trafficking — were invoked using the International Emergency Economic Powers Act, or IEEPA.
It was unclear if Trump’s newly unveiled Iran-related tariffs also rest on that law.