Negotiators from the United States and Iran are set to begin peace talks in Switzerland on Sunday, with the Iranian delegation already in the country and US Vice President JD Vance en route, even as Washington and Tehran clash over Iran's claim that it has closed the Strait of Hormuz.
A high-level Iranian team arrived in Switzerland on Saturday for the talks, Iranian state media reported, while Vance departed Washington for meetings that Pakistan said would begin on Sunday.
The negotiations come amid fresh uncertainty over the strategic waterway. Although the United States and Iran agreed to a 60-day ceasefire to facilitate talks, Iran's Islamic Revolutionary Guard Corps (IRGC) declared the Strait of Hormuz closed on Saturday. The US military, however, said commercial shipping continued to move through the passage.
The dispute threatens to complicate efforts to advance an interim agreement brokered by Pakistan and signed on Wednesday by US President Donald Trump and Iranian President Masoud Pezeshkian, aimed at ending nearly four months of conflict.
Citing what it described as Israeli "crimes" in Lebanon and alleged US failure to uphold ceasefire commitments, the IRGC warned vessels against approaching the strait, a critical artery for global oil and gas supplies. US Central Command countered that 55 merchant ships carrying more than 17 million barrels of oil and other cargo transited the waterway on Saturday and said American forces would ensure the continued flow of commercial traffic.
The Iranian delegation is led by chief negotiator Mohammad Baqer Qalibaf and includes Foreign Minister Abbas Araqchi, along with senior security, central bank and oil officials. The U.S. team includes Vance, special envoy Steve Witkoff and presidential adviser Jared Kushner.
Iranian Foreign Ministry spokesperson Esmaeil Baghaei said Tehran would use the talks to press for implementation of commitments under the agreement, pointing to what he described as a history of the other side failing to honour its obligations.
Vance, meanwhile, said he remained confident the ceasefire would hold and that he had seen no evidence the Strait of Hormuz had actually been closed.
The US vice president left for Switzerland shortly after 4 p.m. ET on Saturday and said negotiators were likely to hold a "couple days of talks."
"I think we're going to hopefully make progress on the nuclear issue, make progress on the Lebanon ceasefire issue," Vance told reporters before boarding his flight.
A halt to fighting in Lebanon was one of the key conditions for launching the US-Iran talks on Tehran's nuclear programme and other issues. Yet the ceasefire remains fragile. Lebanon's Civil Defence said Israeli strikes killed 20 people on Saturday, just hours after a truce took effect.
Israel said it was responding to attacks by Hezbollah, while the Iran-backed group said it would not allow Israel "freedom of movement" in Lebanon.
Israel, which is not a party to the US-Iran agreement, has said it will maintain its military presence in Lebanese territory under its control. According to Israeli broadcaster Channel 12, Prime Minister Benjamin Netanyahu and Defence Minister Israel Katz instructed the military to hold fire but not withdraw from captured areas.
A poll conducted by Hebrew University and shared exclusively with Reuters found that 92% of Israelis believe Iran benefited more than Israel from the joint Israeli-US military campaign. Nearly 90% said the war's objectives had not been achieved, while more than 70% said they did not believe Netanyahu's claims of major gains.
Lebanon's state news agency NNA reported that Israeli warplanes and drones struck targets across southern Lebanon and the Bekaa Valley on Saturday, both considered Hezbollah strongholds.
An Israeli military official said Hezbollah fired more than 50 projectiles at Israeli forces overnight, prompting retaliatory strikes on what Israel described as Hezbollah targets.
The Israeli military said it remained committed to the ceasefire but would continue to act against any threat to Israel or its forces.
Lebanon's health ministry says 4,057 people have been killed in Israeli attacks since March 2, including women, children and medical personnel, although it does not distinguish between civilians and combatants.
Israeli authorities say at least 32 soldiers and four civilians have been killed in fighting involving Hezbollah.
Meanwhile, Switzerland's Foreign Ministry has welcomed the arrival of the Iranian delegation ahead of talks with US officials in Burgenstock.
The Iranian delegation is on its way to the Brgenstock as part of the implementation of the MoU signed between the US and Iran, it said in a post on X.
