This link is to a TIME article, which is fine. The actual letter from the Iranian government can be read here, and I recommend doing so.

As the first casualty of the endless wars waged by the U.S. government has without exception been the truth, with the American people perpetually receiving the greatest harm as the result of the U.S. government’s campaign of deception, we wish to highlight some of the facts that are being withheld from the American public. After all, it is the American taxpayers who will have to bear the cost of America’s unjust wars, and so they deserve to know the truth.

The amount of patience that the government of Iran has had with the United States active imperialist belligerence is honestly saintly.