Shipping stalls in Strait of Hormuz after Iran declares key waterway closed again

Oil tankers and cargo vessels remain anchored off Port Sultan Qaboos on June 21, 2026 in Muscat, Oman. The Strait of Hormuz, a vital shipping route for the region's oil and gas, was effectively blockaded since the outbreak of war between the United States and Iran in late February. On Sunday, U.S. Vice President JD Vance arrived in Switzerland for high-level talks with the Iranian delegation, as the two sides seek to clarify the terms of ending the war. Elke Scholiers | Getty Images News | Getty Images Shipping through the Strait of Hormuz stalled over the weekend, according to maritime intelligence company Windward, after Iran announced it had again closed the world's most important oil choke point. The update comes even as industry trackers showed Iranian tankers continued to sail through the strait, a narrow waterway that typically handles around 20% of the world's oil traffic. There was a recovery in oil tanker traffic through the strait immediately after the U.S. and Iran signed a 14-point memorandum of understanding (MOU) last week but the latest data shows this has already hit a snag. An analysis published by Windward found that a total of 12 ships transited the Strait of Hormuz on Sunday, down from more than 21 the previous day. Five of eight inbound vessels were said to be dark, which is when a ship disables its Automatic Identification System (AIS) transponder to hide its location, identity and destination. …