Iran has warned it could disrupt shipping across key regional waterways, including the Red Sea, in response to US restrictions on vessels entering or leaving Iranian ports. It marks a broadening of Tehran's maritime threat beyond the strait of Hormuz, where vessel traffic has already slowed sharply since the conflict between the US and Iran started in late February.
Ali Abdollahi, head of Iran's Khatam al-Anbiya Central Military Headquarters — the country's highest operational military command — said continued US actions targeting Iranian ports and tankers would "constitute a prelude to a violation of the ceasefire" between Washington and Tehran. He warned Iran would respond by preventing "any exports or imports to continue in the Persian Gulf, the Sea of Oman, and the Red Sea" if the US blockade persists.
The US began a naval blockade on vessels entering or leaving Iranian ports on Monday. The US military said no vessels breached the restrictions in the first 24 hours. It said several ships had been instructed to turn around and return to Iranian ports.
Vessels calling at or leaving non-Iranian ports are not subject to the measures. At least seven ships transited the strait of Hormuz over the past 24 hours with AIS signals active, according to ship-tracking data from Kpler and MarineTraffic.
Despite the escalation in rhetoric, both sides have signalled scope for renewed diplomacy. US president Donald Trump told ABC News that the conflict could end "very soon". Vice-president JD Vance, who led the US delegation in recent talks, said he remained positive about the trajectory of negotiations following discussions in Islamabad that ended without a breakthrough.
The statements have raised expectations that US and Iranian officials could return to Pakistan, or another venue, for further talks.
Washington has continued to portray regional instability as driven by Tehran and its allies. Speaking at the UN on 14 April, US representative Jennifer Locetta said Iran continues to enable destabilising activity across the region, including support for Yemen's Houthi movement.
The US has accused the Houthis of launching repeated missile and drone attacks on shipping in and around the Red Sea and has called for tighter compliance with UN inspection mechanisms for vessels bound for Houthi-controlled ports.

