Iran Closes Strait of Hormuz to Commercial Vessels Amid US Blockade

Iran's military has announced that the Strait of Hormuz is returning to "strict control", with passage through the key shipping lane now requiring Iranian approval. This decision, communicated by the Islamic Revolutionary Guard Corps (IRGC) and other state media on April 18, 2026, comes in direct response to the United States' refusal to lift its naval blockade on Iranian ports in the Persian Gulf. Iranian officials, including the commander for Khatam al-Anbiya Central Headquarters, Ali Abdollahi, warned that if the US blockade continues, creating insecurity for Iranian commercial vessels, it would be a "prelude to a violation of the ceasefire." Iran further threatened that if its own ports are jeopardized, no ports in the Persian Gulf and Sea of Oman will be safe, and it would prevent all exports and imports in the Persian Gulf, Sea of Oman, and the Red Sea. The US military had previously stated its intention to enforce a blockade on traffic entering and leaving Iranian ports from Monday 10 a.m. ET following failed negotiations.