This was stated by US President Donald Trump on Truth Social.
"This order is definitely final," he wrote.
Among Iran's largest trading partners are China, Turkey and the United Arab Emirates, according to AFP.
The announcement of tariffs comes at the same time as Trump is said to be considering how the United States can and should punish Iran after demonstrations critical of the government were violently suppressed.
"Airstrikes would be one of many, many options being considered," White House press secretary Karolina Leavitt said.
