Iran's top joint military command, ​Khatam al-Anbiya Central ‌Headquarters, said on Saturday that the Strait ​of Hormuz would ​be closed to vessel ⁠traffic, citing ​alleged violations of a ​ceasefire agreement by the U.S. and Israel, Iran's ​Mehr state ​news agency reported.

It said that ‌the ⁠closure was the "first step" in response to what it described as ⁠breaches of commitments and warned that further measures would ⁠be taken if "aggression" continued.Reuters reported.

The Islamabad Memorandum of Understanding between Iran and the United States was signed in the first minutes of June 18, 2026, by Iranian President Masoud Pezeshkian and US President Donald Trump through a simultaneous digital process without an in-person ceremony.

Iranian officials described the document as a political framework designed to end the imposed US-Israeli war of aggression against the Islamic Republic of Iran and create a pathway toward a comprehensive final agreement. The memorandum was finalized after weeks of negotiations and signed in both Persian and English.