Iran said it has closed the Strait of Hormuz for shipping transit due to what it called Israel’s violation of a ceasefire, even as Pakistan said US-Iran talks were set to open in Switzerland on Sunday.
The Hormuz action casts a new cloud over the talks, which are aimed at permanently ending a conflict that’s thrown the Middle East into disarray. The immediate impact on vessel traffic was unclear, but even before the recent ceasefire, millions of barrels of oil had been quietly escaping the waterway each day.
Iran’s joint military command said the closure is Iran’s first step in response to Israel’s continued attacks in southern Lebanon, the semi-official Tasnim news agency reported on Saturday.
Negotiations on a peace deal were meant to start on Friday, but were delayed after fighting between Israel and Iran-backed Hezbollah militants in Lebanon intensified. Iranian state TV reported Saturday that a delegation was now en route to the talks, which Pakistan’s foreign ministry said will open on Sunday.
Vice President JD Vance, who had originally planned to be in Switzerland on Friday, said US envoys Steve Witkoff and Jared Kushner were already there laying the groundwork for technical talks, and that he hoped to travel there in “the next couple of days.”
“I am very confident we can maintain the ceasefire,” he said in an interview with Fox News. “We’re going to give this negotiation a chance.”
The Iranian delegation heading to Switzerland includes Parliament speaker and top negotiator Mohammad Bagher Ghalibaf, Foreign Minister Abbas Araghchi and Central Bank Governor Abdolnaser Hemmati, according to the state-run IRIB News.
Hopes were running high that normal traffic would resume through the strait, a conduit for about a fifth of the world’s oil and natural gas before the war, after US President Donald Trump signed a memorandum of understanding with his Iranian counterpart, Masoud Pezeshkian, to end dual blockades. But the announcement about a new closure suggests the optimism may have been premature.
Ships have been crossing Hormuz using two routes in recent weeks: one by the coast of Iran and another to the south of the waterway by the Omani coast. Iran said in guidance to shipping this week that no ship would cross the waterway without its permission. The middle section between those two routes is believed to have been mined during the war.
On Saturday, US Central Command said commercial ship traffic increased in the strait, with 55 merchant ships transiting cargo and more than 17 million barrels of oil.
“Iran announced the closure of the Strait, but it is not clear yet if that is more than rhetoric,” said Daniel Shapiro, a former US ambassador to Israel and senior fellow at the Atlantic Council. “Meanwhile, they are sending negotiators to Switzerland. That suggests they do not want to lose the benefits they are promised in this MOU.”
Alaeddin Boroujerdi, an Iranian lawmaker and member of parliament’s national security and foreign policy commission, said the Hormuz closure by the Islamic Revolutionary Guard Corps was a reaction to the one-sided implementation of the initial ceasefire deal.
“It’s only natural that we utilize our leverage,” he said on state TV. “This move marks our first serious operational step, which we hope proves effective. The other side must not act in a manner that compels the IRGC to deploy alternative levers of pressure.”
Still, even before the US-Iran ceasefire, oil tankers were using the Omani route by transiting at night with their satellite signals turned off. In recent days, vessels appeared to transit Hormuz using both routes, including earlier on Saturday.
Iran’s declaration on Saturday will likely make more risk-averse shipowners with vessels that have been trapped inside Hormuz for months more wary of exiting. Earlier in the day western naval forces had said vessels using the corridor could cross at any time and with their satellite signals either on or off.
“I expect this to happen again and again over the next couple of days and weeks,” said Martin Kelly, head of advisory at EOS Risk Group. “Iran is using its leverage over the Strait of Hormuz to try and force a ceasefire in Lebanon.”
Kelly added that there have been other instances of Iran saying Hormuz is shut since the US-Iran ceasefire was agreed “but they didn’t really enforce it.” Some shipowners had reported hearing radio broadcasts from Iran that Hormuz was closed earlier in the week.
Oil rose slightly on Friday, with Brent up about 0.9% to $80 per barrel, paring gains for the week to about 7.7%. The price remains roughly 30% higher for the year because it will take months for flows to return to normal, and could jump again when markets reopen next week unless the deadlock over Lebanon is resolved.
While Israel and Hezbollah separately said they had agreed to a truce on Friday, violence has persisted.
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The Lebanese army said in a post on X on Saturday that Israel had attacked the south of the country and the Bekaa valley, causing fatalities, injuries and extensive destruction of property. Lebanon’s state-run National News Agency said five people were killed around the southern town of Nabatieh.
Hezbollah said on Telegram that its forces confronted Israeli troops who tried to advance in Nabatieh overnight and entered an ambush. It said it had abided by the ceasefire since Friday evening, but won’t tolerate “any attempts by the enemy to seize land and expand its occupation.”
Meanwhile, the Israel Defense Forces said it had struck Hezbollah targets, including weapon storage facilities, rocket launch positions and command centers, after the group fired more than 50 projectiles at its forces in southern Lebanon overnight. While the IDF is committed to the truce, it will “continue to operate to remove any threat” posed to Israel and its soldiers, it said in a statement.
A delay in reaching a deal with Iran would be a blow to Trump, who has faced criticism that he was conceding too much in terms of financial benefits and relief from sanctions. He had said the agreement would prevent a global economic crisis, given the critical Strait of Hormuz would fully reopen.
Iran has been “completely defeated militarily,” Trump posted on Truth Social on Saturday. “Iran got away with ‘murder’ for 47 years, until I came along. Then it all changed.”
On Friday, he said the two sides still have time to reach an agreement.
“Otherwise, we will do things that won’t make them happy, but I don’t think it’s going to get to that,” he said in remarks at Joint Base Andrews, where he was unveiling the new Qatar-gifted jet that will serve as Air Force One.
The war in the Middle East erupted when the US and Israel launched air strikes on Iran on Feb. 28. The Islamic Republic struck back, firing missiles and drones at Israel and nations across the Gulf, and thousands of people were killed.
Strains between the US and Israel over Lebanon are growing. Trump has sworn at Israeli Prime Minister Benjamin Netanyahu in calls, accusing him of almost scuppering the memorandum with Iran by escalating strikes. Israel insists it will keep troops across its borders until it’s sure Hezbollah, designated a terrorist organization by the US, is no longer a threat.
A poll aired on Israel’s top-rated Channel 12 TV showed 67% of Israelis see the US-Iran deal as bad for their country, 9% see it as good and the remainder are undecided.
The US and Israel say they attacked Iran to stop it from building an atomic weapon. Tehran has long denied wanting to do that, but has enriched uranium to far beyond the levels needed for nuclear power plants.
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