Iran Closes Strait of Hormuz Ahead of Key US-Iran Talks

Iran’s military announced the closure of the Strait of Hormuz on Saturday, hours before U.S. and Iranian negotiators were scheduled to meet in Switzerland for critical talks aimed at finalizing a nuclear agreement. The dramatic escalation, which threatens approximately 20% of the world’s daily oil supply, came as Israeli strikes in southern Lebanon killed at least 16 people, including two children, according to The Associated Press.

Conflicting Claims Over the Strait’s Status

Iran’s joint military command, the Khatam al-Anbiya Central Headquarters, and the Islamic Revolutionary Guard Corps (IRGC) Navy declared the waterway closed, warning all vessels to stay away. The statement cited continued Israeli military operations in Lebanon and what Tehran described as U.S. “bad faith” in upholding commitments under the interim truce framework signed just days earlier.

However, the U.S. military flatly denied Iran’s assertion. “Iran does not control the Strait of Hormuz. Traffic continues to flow, and U.S. forces are monitoring the situation to ensure this remains the case,” said Capt. Tim Hawkins, a spokesperson for U.S. Central Command, as reported by CNBC. The U.S. military reported that 55 merchant ships transited the strait on Saturday, carrying more than 17 million barrels of oil.

Trump Threatens U.S. Tolls on the Waterway

President Donald Trump weighed in on the standoff with a provocative new threat. In a post on Truth Social, Trump declared there would be “NO TOLLS in the Hormuz Strait for 60 days” but warned that the U.S. could impose its own tolls if a final deal is not completed within that window, calling them payment for “services rendered as the Guardian Angel to the countries of the Middle East.” The suggestion of U.S.-imposed tolls on an international waterway represents a significant escalation in rhetoric with no clear legal basis under international maritime law.

Talks Proceed Despite Tensions

Despite the heightened tensions, diplomatic channels remain open. U.S. Vice President JD Vance departed for Switzerland on Saturday evening, where technical-level talks are scheduled to begin Sunday. The Iranian delegation, led by parliamentary speaker Mohammad Bagher Qalibaf and including Foreign Minister Abbas Araghchi, had already arrived. Mediators from Pakistan and Qatar are also participating, according to Xinhua News.

Vance struck an optimistic tone before departing, telling reporters that despite “the headlines, things are actually getting better there (in Lebanon), and things are slowing down a little bit.” He confirmed that top negotiators Jared Kushner and Steve Witkoff were already in Switzerland working through technical details.

Iran Links Strait Closure to Israel’s Actions in Lebanon

Iran’s announcement was explicitly tied to events on the ground in Lebanon. Israeli airstrikes on Saturday hit the southern city of Nabatiyeh and nearby villages, with seven people still trapped under rubble, according to Lebanese authorities. Hezbollah fired more than 50 projectiles at Israeli forces in southern Lebanon overnight. The death toll in the Israel-Hezbollah war has now surpassed 4,000.

A Hezbollah official told the AP that Iran informed the militant group it would not reopen the strait until Israel publicly commits to a “comprehensive ceasefire” in Lebanon. The official said Hezbollah would commit to a ceasefire if Israel does. Neither Israel nor Hezbollah are signatories to the U.S.-Iran interim agreement, creating a fundamental gap in the deal’s enforceability.

The Interim Agreement at Risk

The closure announcement came just three days after Trump and Iranian President Masoud Pezeshkian signed a memorandum of understanding on June 17, ending nearly four months of hostilities that began with U.S.-Israeli airstrikes on Iran on February 28. The deal called for an immediate end to military actions by Israel in Lebanon, full reopening of the strait without tolls for 60 days, and a framework for negotiations on Iran’s nuclear program.

Iranian Foreign Ministry spokesperson Esmail Baghaei warned that “the memorandum of understanding as a whole will be jeopardized” if the U.S. fails to uphold its commitments, speaking to Iranian state TV.

Global Economic Fallout

The crisis has already triggered severe disruptions in global energy markets. The International Energy Agency has described the situation as the “largest supply disruption in history.” China, the world’s largest oil importer, has stockpiled an estimated 900 million barrels — roughly three months of imports — and ordered its refineries to stop exporting fuel to keep domestic prices under control, as BBC News reported. Countries from the UK to Sri Lanka have implemented emergency measures including fuel rationing, free public transport, and price controls.

What to Watch

As negotiators gather in Switzerland, several critical questions remain unanswered: Is the strait actually closed, partially restricted, or fully open? Can the U.S. enforce Trump’s toll threat under international law? Will Israel comply with a ceasefire in Lebanon? And perhaps most urgently — how will global oil markets react when trading opens on Monday?

The coming days will determine whether the fragile interim agreement can survive its first major test, or whether the world faces a prolonged energy crisis with no clear diplomatic off-ramp.