Iranian Supreme Leader Mojtaba Khamenei declared on 19 July that repeated US military strikes on Iran — despite a peace memorandum of understanding (MoU) signed as recently as 18 June — have exposed US President Donald Trump's signature as 'worthless and invalid,' according to Iranian state media. The statement marks a sharp escalation in rhetoric as active hostilities continue across the region.

Khamenei's Warning to Washington

In a message to the Iranian people carried by state media, Khamenei said the frequent US violations of the MoU — signed between Iranian President Masoud Pezeshkian and Trump — 'once again proved to everyone the fact that how worthless and invalid the US president's signature is.' He described the pattern as 'another solid proof of the US lying and its illogical, unreliable, and evil nature,' and said the United States had 'once again revealed its true and unmasked face.'

Khamenei warned that if Washington continued what he termed warmongering and sought to impose heavier costs on Iran, it should expect 'unforgettable lessons' from Iran and what he called the resistance front.

Iran Suspends MoU Commitments

Earlier on Saturday, Iranian Deputy Foreign Minister for Legal and International Affairs Kazem Gharibabadi announced that Iran had ceased fulfilling its obligations under the MoU, accusing Washington of violating or suspending 'all its commitments' under the deal. Speaking on state-run IRIB TV, Gharibabadi said Iran is now focused solely on self-defence, adding: 'There is no news of negotiations.'

'What we are currently faced with is defending the country in a decisive manner,' Gharibabadi said. 'This time too, the Americans have already received their answer that these aggressive actions will lead nowhere. If they are wise, they should choose other solutions.'

Military Exchanges Intensify

The United States has launched multiple waves of strikes on military sites and infrastructure in Iran's southern provinces over the past week, claiming the operations were aimed at 'degrading Iran's ability to threaten commercial shipping' in the Strait of Hormuz. Iran has responded with missile and drone attacks targeting US military bases and facilities in several Gulf countries and Jordan.

The MoU, signed on 18 June, had envisaged negotiations within 60 days toward a final agreement. That diplomatic window now appears effectively closed, with both sides trading strikes rather than proposals.

Regional Spillover: Kuwait and Bahrain

The conflict has spilled well beyond Iran's borders. Kuwait and Bahrain confirmed on Saturday that their air defence systems intercepted fresh rounds of Iranian aerial attacks. A key oil facility and a power generation and water desalination plant in Kuwait were struck, raising concerns about energy infrastructure security across the Gulf.

What Comes Next

With Iran formally suspending its MoU obligations and Khamenei threatening 'unforgettable lessons,' the diplomatic path toward a final agreement appears severely damaged. Analysts warn that continued strikes on Gulf energy and water infrastructure risk broader economic disruption, particularly given the Strait of Hormuz's role in global oil transit. Whether back-channel contacts survive the current military exchange remains to be seen.