Iran on Saturday announced the closure of the Strait of Hormuz to vessel traffic, accusing the United States of a "clear breach of trust" and Israel of violating the ceasefire in southern Lebanon, a move that threatens to undermine a fragile US-Iran agreement and reignite concerns over global energy supplies.
According to Iran's semi-official Mehr news agency , the country's top joint military command said the strategic waterway was being shut in response to Washington's "clear breach of its commitments" under the first clause of the memorandum of understanding (MoU) that ended the Middle East war, as well as Israel's continuing military operations in southern Lebanon.
You may follow our live coverage of the West Asia war here
Iran's Islamic Revolutionary Guard Corps (IRGC) confirmed that Strait of Hormuz had been closed to all vessels and warned ships against approaching the waterway, saying their security would otherwise be at risk, according to Reuters .
The warning marked a significant escalation in Tehran's messaging, signalling an attempt to enforce the closure of one of the world's most strategically important maritime chokepoints even as Washington maintained that it had seen no evidence of a blockade.
The command described the closure as the "first step" and warned that "if the aggression continues, subsequent steps have been planned."
The decision is a dramatic reversal especially as ships had resumed transiting Hormuz following the signing of the interim US-Iran agreement earlier this week. Iran had previously closed the passage during the war, disrupting one of the world's most important routes for oil and liquefied natural gas shipments.
Washington sees no blockade, bets on diplomacy
Despite Tehran's announcement, US Vice President JD Vance said Washington had seen no evidence that Iran had actually shut the Strait of Hormuz.
Speaking to Fox News , Vance said talks with Tehran were progressing well and expressed confidence that the ceasefire could be maintained. He said negotiations with Iran could take place as early as Sunday and that the United States intended to "give Iran negotiations a chance."
Vance also said US special envoy Steve Witkoff and Jared Kushner were on the ground for talks related to Iran and added that he expected to travel to Switzerland in the coming days.
Lebanon flare-up threatens fragile truce
Tehran directly linked the closure of the Strait of Hormuz to developments in Lebanon, where Israeli strikes in southern parts of the country killed at least 16 people, including two children, on Saturday. Seven others were reported trapped under the rubble after strikes in and around the town of Nabatiyeh.
The latest violence followed a heavy exchange of fire on Friday that reportedly killed at least 47 people in Lebanon and four Israeli soldiers.
The Israeli military said Hezbollah had fired more than 50 projectiles at Israeli forces in southern Lebanon overnight, prompting strikes on dozens of Hezbollah targets, including rocket-launching positions and command centres. Hezbollah, meanwhile, said it remained committed to the ceasefire but accused Israel of violating the agreement multiple times and said it would repel any attacks by Israeli troops.
Also read: Congress wonders as the Iran war draws to a close: Was it worth it?
Neither Israel nor Hezbollah is a signatory to the US-Iran deal, although the agreement calls for military operations in Lebanon to cease and for the country's sovereignty to be respected. The continued fighting has raised questions over the viability of the accord and threatened to derail the next phase of diplomacy.
Tehran heads to Switzerland, seeks guarantees
Even as it accused Washington of failing to honour the agreement, Tehran indicated that diplomacy had not collapsed.
Iran's Fars news agency , citing Foreign Ministry spokesperson Esmail Baghaei, said an Iranian delegation would travel to Switzerland to follow up on the implementation of the MoU and demand fulfilment of the other party's commitments.
The announcement marks a shift from earlier indications that Iran could suspend its participation in the talks because of the continued fighting in Lebanon. Switzerland has confirmed that confidential discussions between the United States and Iran remain underway and that it continues to provide a neutral setting for implementing the agreement.
Also read: Iranian state TV says the country's team negotiating with US over the war is going to Switzerland
The Strait of Hormuz, located between Iran and Oman, remains one of the world's most critical energy chokepoints, carrying a significant share of global seaborne crude oil and liquefied natural gas shipments.
The interim US-Iran accord gives negotiators 60 days to work towards a final deal on Iran's nuclear programme and envisages sanctions relief, the unfreezing of Iranian assets and broader economic normalisation. But with fighting continuing in Lebanon and Tehran once again threatening maritime traffic through Hormuz, the agreement is facing its first major test only days after it was signed.
