US-Iran war: Maritime blockade risks oil flows in 2026

Blockade begins after talks fail in Pakistan

The US military has begun enforcing a maritime blockade on all traffic to and from Iranian ports starting April 13, following ceasefire talks in Pakistan that ended without a breakthrough. US Central Command (CENTCOM) said the restrictions would apply to vessels of all nations entering or exiting Iranian ports and coastal areas. The development marks a sharp escalation in the maritime dimension of the US-Iran confrontation, with immediate focus on energy shipments and commercial routes around the Arabian Gulf.

The blockade announcement comes amid heightened uncertainty after a brief period in which a ceasefire had been in place, and shipping activity through the Strait of Hormuz had been closely watched. Early market reaction was visible in oil, with reports of upward movement in prices in early trading.

Trump says war is “very close to over”

US President Donald Trump said he believes the war with Iran is “very close to over,” in an interview with Fox Business Network’s Mornings with Maria. In the same interview, Trump said that if he “pulled up stakes” right now, it would take Iran “20 years to rebuild that country.” He also said, “And we’re not finished,” adding, “We’ll see what happens.”

Trump further said he believes Iran wants a deal “very badly.” Separately, he indicated that talks aimed at ending the conflict could resume in Pakistan over the next two days, after the earlier efforts in Islamabad collapsed.

CENTCOM’s order: timing and enforcement

CENTCOM said the blockade would take effect at 10 a.m. ET on Monday, which it translated as 7:30 p.m. India time and 2:30 p.m. GMT. The command said enforcement would be “impartial” and would cover maritime traffic entering and exiting Iranian ports and coastal areas, including facilities along the Arabian Gulf and the Gulf of Oman.

President Trump announced the operation on Sunday, saying the US Navy would move to block maritime access following the breakdown of negotiations. Subsequent military messaging clarified how the policy would be applied on the water.

What the blockade covers, and what it does not

CENTCOM’s description focused on vessels entering or departing Iranian ports and coastal areas. At the same time, it said freedom of navigation through the strategically vital Strait of Hormuz would not be impeded for vessels heading to or from non-Iranian ports.

This distinction matters because it signals a targeted attempt to isolate Iranian maritime activity while seeking to limit disruption to broader international transit. Still, the policy is occurring in a corridor that is central to global energy and shipping, and even partial restrictions can raise risk premiums for freight, insurance, and commodity pricing.

First 24 hours: “no ships have passed,” six turned back

CENTCOM said it successfully blocked all vessels traveling to and from Iranian ports and coastal areas in the first 24 hours of the blockade. It said the blockade is being enforced impartially against vessels of all nations entering and exiting Iranian ports.

CENTCOM added that six merchant vessels complied with US directions to turn around. The update provided an early snapshot of enforcement effectiveness and compliance by commercial shipping.

Trump’s claims on Iran’s navy and the threat warning

Trump posted that Iran’s navy was “completely obliterated,” claiming “158 ships” were at the bottom of the sea. He also wrote that he had not ordered strikes on Iran’s “fast attack ships,” describing them as not much of a threat.

In the same post, Trump warned that if ships come close to the blockade, they would be “immediately eliminated.” These statements were made around the same period the blockade was set to begin at the 10 a.m. ET deadline.

Mine-clearing operations in the Strait

CENTCOM also confirmed that mine-clearing operations had begun to ensure safe passage through the Strait of Hormuz. The mine-clearing detail underscores the operational risk around the waterway during periods of military escalation, even when authorities state that transit to and from non-Iranian ports will be allowed.

The combination of enforcement actions and safety operations highlights how quickly commercial conditions can change for shipping lines and energy cargoes in the region.

Iran’s response and Strait of Hormuz posture

Iran’s Armed Forces Central HQ responded to the blockade by warning that “Security in the PersianGulf and the Sea of Oman is either for everyone or for NO ONE.” It added: “If Iran’s ports are threatened, NO PORT in the region will be safe.”

Separately, the live updates also described Iranian claims around control of the Strait of Hormuz, reflecting an escalating contest over leverage in one of the world’s most strategically sensitive chokepoints.

Why markets are watching: oil, shipping, and India’s risk lens

The escalation has raised immediate concerns over global oil supplies, shipping routes, and regional stability, with oil prices already showing upward movement in early trading. For Indian investors, the most direct channel is crude sensitivity across fuel-linked sectors and broader inflation expectations, even before company-level impacts are visible.

A second channel is freight and insurance costs tied to Middle East routes, which can affect landed costs for imports and export logistics timing. The blockade’s stated design to avoid impeding non-Iran-related transit through Hormuz may limit disruption compared with a full closure, but the presence of active enforcement and military warnings can still influence shipping behaviour.

Key facts at a glance

What to watch next

The next focal point is whether US-Iran talks resume in Pakistan within the timeframe Trump cited, and whether any diplomatic step changes the scope or duration of the blockade. Investors will also track follow-on guidance from CENTCOM on enforcement rules, alongside shipping activity indicators and oil price reaction.

For markets, the key near-term variable is not only physical supply but also perceived risk around the Strait of Hormuz and nearby routes, particularly given the mix of military operations, mine-clearing activity, and public threat messaging.