Iran’s Supreme Leader Mojtaba Khamenei says the United States has repeatedly breached a memorandum of understanding (MoU) signed by the presidents of Iran and the United States, and argues that President Donald Trump’s signature is therefore “worthless.” In written statements shared on social media, Khamenei describes the repeated breaches as “utterly worthless and devoid of credibility” and says they show the MoU is invalid in practice. He also warns of “unforgettable lessons” for the U.S., with some reporting framing this as a threat of consequences for the U.S. Army if attacks continue. The statements come as Iran and the U.S. exchange strikes after a ceasefire arrangement broke down last week. Multiple outlets report that Tehran suspended or did not continue commitments under the interim agreement, citing U.S. noncompliance. The renewed fighting has heightened concerns about a broader return to all-out war, with observers and reporting noting potential risks to regional security and global energy supplies.