The confrontation between Iran and the United States in the Strait of Hormuz is entering a new phase, as Tehran plans to declare a “prohibited zone” outside the strait in the coming days, amid a decline in commercial shipping to its lowest level since May and escalating attacks targeting vessels and oil tankers.
اضافة اعلان
The Iranian move is putting maritime traffic at the center of the confrontation with Washington once again. This time, however, it goes beyond the question of closing or reopening the strait to an attempt to impose new restrictions on vessels passing through it, as the United States intensifies its naval and economic blockade of Iran.
Iranian Supreme National Security Council Secretary Mohsen Rezaei said Sunday that Tehran would announce a “prohibited zone” in the coming days, starting from the line of the blockade imposed by the US Navy and extending toward the Strait of Hormuz to include parts of the Gulf.
Rezaei said any vessel entering the zone with the intention of passing through the strait and identified by Iran would be placed on Iran’s sanctions list. He did not specify the zone’s exact geographical boundaries or when the measure would take effect.
The move comes as data from shipping analytics firm Kpler showed that the average number of commodity vessels passing through the Strait of Hormuz over the past 10 days had fallen to 10 vessels per day, the lowest level since May, following recent US and Iranian strikes targeting tankers.
According to the data, only two vessels passed through the strait on Saturday and six on Sunday, most using the Iranian route, highlighting the growing risks facing commercial shipping through the strategic waterway.
New Transit Restrictions
Tehran has yet to disclose how the “prohibited zone” will be enforced or what measures will be taken against vessels entering it, raising questions over whether the move will be limited to placing vessels on sanctions lists or include on-the-ground measures to prevent them from passing through.
Rezaei said Iran was monitoring US vessels attempting to transit routes it considers “illegal,” adding that Iranian measures in the strait would become stricter.
He said Iran had not decided to sink oil tankers because of the environmental damage that could result, arguing that the impact of Iranian measures and sanctions in the strait would be greater than that of missiles.
Rezaei also said Iran and Oman had agreed on a map for vessels entering and leaving the Gulf, adding that an agreement on the matter would be signed soon.
The Iranian official described the Strait of Hormuz as “fully closed,” a claim that contrasts with the US position and maritime tracking data showing that vessels continue to pass through the strait, albeit at significantly lower levels than before the war.
Tankers Become a Battleground
The announcement follows a significant escalation in the maritime confrontation between Washington and Tehran. On Saturday, US forces targeted three Iranian oil tankers after the US military said the Islamic Revolutionary Guard Corps had launched ballistic missiles toward US warships in the region.
Iran responded by targeting vessels and tankers that it said were using unauthorized routes, while the United States threatened to sink Iranian tankers if Tehran continued targeting US naval vessels.
Maritime data indicate that the risks now extend beyond military vessels. Maritime intelligence firm Marisks said the latest developments represented a major escalation, as commercial tankers had become part of the two sides’ economic pressure campaign against each other.
The United Kingdom Maritime Trade Operations agency recorded 27 incidents involving projectile strikes in and around the Strait of Hormuz since July 6, causing varying degrees of damage to vessels.
Rezaei said Iran had tested an anti-ship missile against a US warship for the first time, claiming that US vessels withdrew after the missile was used.
The US military, however, denied Iran’s claim that an unmanned US military vessel had been hit in the strait.
Hormuz Amid US Blockade
The maritime escalation comes as Washington tightens economic pressure on Tehran, after the United States expanded the scope of secondary sanctions that can be imposed on entities and countries conducting commercial transactions with Iran as part of its “Economic Outcast” operation. This coincides with the reimposition of a naval blockade on Iranian ports along the Strait of Hormuz.
Washington says the measures are aimed at increasing economic pressure on Tehran, while Iran says the resumption of the naval blockade undermines the memorandum of understanding reached by the two sides on maritime navigation.
Iranian Parliament Speaker and chief negotiator Mohammad Bagher Ghalibaf said Sunday that Iran must find new alternatives to confront economic pressure targeting supply chains.
He added that any future attacks targeting Iran’s security or interests would be met with a “faster, stronger and more painful” response, saying the United States must understand that “the rules of the game have changed.”
Meanwhile, the commander of Iran’s border guards said his forces were prepared to confront any threat or aggression, stressing that they would not allow any violation of the country’s borders.
Why Hormuz Matters
The significance of the escalation lies in the enormous volume of energy that has historically relied on the Strait of Hormuz to reach global markets.
Data from the US Energy Information Administration (EIA) show that oil flows through the strait averaged 20.9 million barrels per day in the first quarter of 2025, rising to 21.6 million barrels per day in the final quarter of the same year.
The war, however, has sharply disrupted energy flows through the strait. Flows fell to 14.9 million barrels per day in the first quarter of 2026 and then to 4.9 million barrels per day in the second quarter, according to the EIA’s latest estimates.
Liquefied natural gas flows through the strait also declined from 10.5 billion cubic feet per day in the final quarter of 2025 to 7.4 billion cubic feet per day in the first quarter of this year, and then to 0.8 billion cubic feet per day in the second quarter.
These figures illustrate the scale of the war’s impact on one of the world’s most important energy chokepoints. Before the war, oil flows through Hormuz accounted for roughly one-fifth of global petroleum liquids consumption and about one-quarter of seaborne oil trade.
The EIA estimates that Saudi Arabia’s East-West Pipeline and the Abu Dhabi pipeline can provide a combined alternative capacity of around 4.7 million barrels per day, compared with more than 20 million barrels per day that passed through Hormuz before the war.
The limited availability of alternatives means that any further disruption to traffic through the strait could affect energy flows, shipping and insurance costs, and oil prices, particularly if the disruption continues for an extended period.
On August 31, the United States carried out strikes on Iranian missile launch platforms on an island in the Strait of Hormuz, before targeting Revolutionary Guard positions the following day. Washington said the strikes were in response to attacks on commercial vessels and US military personnel in the region.
US Vice President JD Vance said the United States would not hold talks with Iran unless it stopped firing on commercial vessels in the strait, while Tehran maintains that the US naval blockade undermines any understanding on freedom of navigation.
The war began on February 28, when Israel and the United States attacked Iran. Tehran responded by closing the Strait of Hormuz, turning the waterway into one of the most prominent tools of pressure in the confrontation.
The announcement of a “prohibited zone,” however, adds a new dimension to the conflict. Rather than focusing solely on closing or reopening the strait, the confrontation is now extending to the rules governing vessel transit and the routes they are permitted to use.
The United States considers Hormuz a vital international waterway and says its forces are working to protect freedom of navigation and maintain energy flows. Iran, meanwhile, links freedom of passage to its security and to the lifting of pressure and the blockade imposed on it.
The impact of Iran’s new zone will ultimately depend on the details Tehran announces regarding its boundaries, enforcement mechanisms and the vessels it will target.
