In a letter circulated among the 176 member states of the International Maritime Organization on March 24, Iran’s Foreign Ministry said “non-hostile vessels” would be allowed transit if they coordinate with Iranian naval forces. The letter stated that ships linked to the United States, Israel, or “other participants in the aggression” against Iran do not qualify for innocent or non-hostile passage.
Iranian Foreign Minister Seyed Abbas Araghchi repeated the position in a March 24 phone call with Chinese Foreign Minister Wang Yi, saying the strait “is open to all and ships can pass safely, but countries that are at war with Iran are not under consideration.”
A similar note was sent to the United Nations Security Council and the UN Secretary-General on May 7. In that letter, Araghchi stressed that normal maritime traffic would resume only when the U.S.-Israeli war stops permanently and the American naval blockade and “illegal” sanctions against Iran are lifted.
Iran tightened its control over the Strait of Hormuz on February 28, hours after joint U.S. and Israeli strikes hit Iranian territory. Since then, shipping through the waterway has collapsed. According to the U.S. Energy Information Administration, daily oil shipments passing through the strait fell by an average of about 6 million barrels in the first quarter of 2026. In peacetime, roughly one-fifth of the world’s crude oil and liquefied natural gas moves through the strait.
As of April 2026, an estimated 1,000 commercial vessels were stuck in a holding pattern in the Persian Gulf region: about 800 ships waiting inside the strait to exit eastbound and roughly 200 ships waiting outside to enter westbound.
Under Iran’s new management system, ships must use a designated corridor close to the Iranian coast and pay a transit fee. The IRGC Navy warned on May 5 that any vessel deviating from this corridor would face “firm action.”
On May 14, Iran’s Revolutionary Guard announced that “more than 30 ships” had been allowed to pass through the strait, including a number of Chinese-flagged vessels. The Guard said the passage began the night before, after an agreement on Iran’s “strait management protocols.” The same week, Iran’s Deputy Foreign Minister Kazem Gharibabadi said 11 out of 13 Indian commercial vessels waiting for passage had been cleared to cross.
The United States has responded with its own blockade. Since April 13, Washington has enforced a naval blockade on ships traveling to and from Iranian ports, aiming to cut off Iranian oil revenues. U.S. Treasury Secretary Scott Bessent told CNBC that by mid-May there had been “no loadings in the past three days” at Kharg Island, Iran’s main oil export terminal. U.S. Ambassador Mike Waltz has said 41 tankers carrying 69 million barrels of Iranian oil are unable to sell their cargo.
At the United Nations, the United States and Gulf states have proposed a new Security Council resolution that threatens Iran with sanctions if it does not halt attacks on shipping, stop imposing tolls, disclose the location of all mines, and allow a humanitarian corridor through the strait. The draft, circulated on May 5, is designed to avoid a veto from China and Russia, both of which blocked an earlier resolution in April.
Iran has urged UN member states to reject the new resolution, calling it a distortion of facts. In his May 7 letter, Araghchi argued the draft makes no mention of the “military aggression and illegal use of force” by the United States and Israel against Iran.
Oil markets have absorbed the disruption, with Brent crude averaging around $106 per barrel in May and June, according to EIA forecasts. Energy analysts caution that any further escalation could send prices sharply higher.
A fragile ceasefire has been in effect since early April, but military tensions remain high. Both the U.S. naval blockade and Iran’s vetting system for transit vessels have stayed in place, leaving the Strait of Hormuz effectively restricted to a narrow, controlled flow of non-hostile shipping.