Reuters: Strait of Hormuz under pressure as Iran controls vessel access

Iran is implementing a multi-tiered clearance system for vessels transiting the Strait of Hormuz as global shipping routes face severe disruption amid war-related energy supply constraints. The United States has warned against compliance with Iran’s arrangements, while some governments and shipping operators are nonetheless engaging with the system to secure passage, Reuters reports.

One tanker, the 330-metre Agios Fanourios I carrying Iraqi crude oil to Vietnam, followed a route designated by Iranian authorities after being stranded near Dubai since late April. On May 10, it entered the strait following a direct arrangement involving Iraq’s prime minister.

“Once we were informed Agios passed Hormuz, we breathed a sigh of relief,” said one person monitoring the voyage.

Iran’s mechanism reportedly involves layered approvals, including government-to-government agreements, security vetting by the Islamic Revolutionary Guard Corps (IRGC), and, in some cases, payments for passage. A European shipping source said some vessels without state agreements have paid more than $150,000.

“The straits will be blocked or opened up only by the approval of the Iranian regime,” said Danny Citrinowicz, an Iran analyst at Israel’s Institute for National Security Studies.

The U.S. Treasury has warned of sanctions risks for any entity making payments to Iran for safe passage. “The department is prepared to take action against any foreign company supporting illicit Iranian commerce,” it said.

Iran prioritises vessels linked to allies such as Russia and China, followed by countries like India and Pakistan, with other ships subject to bilateral arrangements or inspections. Iran’s state institutions, including the Islamic Revolutionary Guard Corps, Ports and Maritime Organization, and a newly established Strait Authority, conduct detailed vetting of ships.

“The affiliation check is to identify if the vessel has any connection to the U.S. or Israel,” a European shipping source said.

Documents reviewed by Reuters show shipowners must disclose cargo value, ownership, crew nationalities, and routing details. Approval can take about a week and may include physical inspections.

In the Agios Fanourios I case, Iranian IRGC speedboats briefly stopped the tanker near Hormuz Island over suspected smuggling before allowing it to proceed. “The Iranians repeatedly asked about the crew's nationality,” said an Indian sailor familiar with similar transits.

Iran has not commented on the reported mechanism. China’s foreign ministry called for Hormuz to remain open, stressing compliance with international law.

By early May, around 1,500 vessels were reportedly stranded in the Gulf, with fewer than 60 passing the strait over an 18-day period, compared with up to 140 daily before the disruption.

Even after clearing Hormuz, the Agios Fanourios I was later intercepted by U.S. forces enforcing a blockade. “U.S. forces directed the Malta-flagged vessel to turn around,” said CENTCOM spokesperson Capt. Tim Hawkins.

By Vafa Guliyeva