Negotiators from the United States and Iran were set to start peace talks in Switzerland on Sunday, even as US officials disputed Iranian claims about closing ​the key Strait of Hormuz.

High-level officials from Iran arrived in Switzerland for peace talks with the US, Iranian state media reported, as US Vice President JD Vance departed Washington for meetings ‌that Pakistan said will begin on Sunday.

Although the US and Iran had agreed to a 60-day ceasefire while negotiations take place, Tehran’s Islamic Revolutionary Guard Corps on Saturday declared the Strait of Hormuz shut, though the US military said commercial vessels had continued operating in the waterway.

Those developments could complicate talks in which both sides seek to advance an interim deal brokered by Pakistan and signed on Wednesday by Presidents Donald Trump and Masoud Pezeshkian to end their almost four-month war.

Hormuz, Lebanon remain flashpoints

Pointing to what it called ​Israeli “crimes” in Lebanon that violated US commitments to a ceasefire, the IRGC warned ships would be at risk if they approached the Strait, a vital conduit for global oil and gas supplies.

But US ​Central Command said 55 merchant ships transited the strait on Saturday with more than 17 million barrels of oil for global markets.

US forces will ensure commercial traffic ⁠continues, Central Command said.

Trump said no toll would be charged for passage through the strait during or after the 60-day ceasefire — unless the US imposes one should peace talks fail.

In a social media post, he cited ​the possibility of a toll levied by the United States “for services rendered as the Guardian Angel to the countries of the Middle East” if a peace deal is not completed.

Mohammad Mokhber, an adviser to Iran’s supreme leader, Ayatollah ​Mojtaba Khamenei, accused the US on X of failing to implement the first clause of its 14-point interim deal with Iran, which includes a ceasefire “on all fronts”, including Lebanon.

He said that, as long as the agreement was only on paper, the flow of Middle East energy would remain halted.

The Lebanon truce appeared fragile as Israeli forces and the anti-Israel group Hezbollah attacked each other.

The Iranian delegation is led by chief negotiator Mohammad Baqer Qalibaf and includes Foreign Minister Abbas Araqchi as well as senior security, central bank ​and oil officials, Iranian media said.

In addition to Vance, the US negotiating team includes envoys Steve Witkoff and Jared Kushner, Trump’s son-in-law.

Iranian Foreign Ministry spokesperson Esmaeil Baghaei said Iran would press in Switzerland for fulfilment of ​commitments, citing past failures by the other side to honour agreements.

Vance, in an interview with Fox ‌News, said ⁠he was confident the ceasefire would hold and that he had seen no evidence that the Strait of Hormuz was closed.

The US vice president left for Switzerland shortly after 4pm ET on Saturday.

Negotiators would likely have a “couple days of talks“, he told reporters before boarding a plane at Joint Base Andrews in Maryland.

“I think we’re going to hopefully make progress on the nuclear issue, make progress on the Lebanon ceasefire issue,” he said.

Israeli strikes in Lebanon continue

A halt to fighting in Lebanon was one of the conditions for starting US-Iranian talks on Tehran’s nuclear programme and other issues.

But Lebanese Civil Defence said 20 people had been killed by ​Israeli strikes in Lebanon on Saturday, hours after a ​truce took effect there.

Israel claimed it was responding to ⁠alleged attacks, while Hezbollah said it would not allow Israel “freedom of movement” in Lebanon.

Israel says it is not a party to the Iran-US deal and will keep its forces in the Lebanese territory it occupies.

A military statement said Israel was committed to the ceasefire but would continue to act against any threat ​to Israel or its forces.

Israeli broadcaster Channel 12 reported that the prime minister and defence minister had instructed the military to hold fire in Lebanon but that ​it would not withdraw from ⁠areas it had captured.

A poll by Israel’s Hebrew University, shared with Reuters, found that some 92% of Israelis believe Iran benefited more from the joint Israeli-US military campaign than Israel, and only some 8% think Israel emerged victorious.

Almost 90% of Israelis said the goals of the war were not met, and more than 70% do not believe Prime Minister Benjamin Netanyahu’s claims that there were major achievements.

Lebanon’s state news agency NNA said Israeli warplanes and drones had struck locations ⁠across southern Lebanon ​and the Bekaa Valley on Saturday.

An Israeli military official alleged that Hezbollah fired more than 50 projectiles at Israeli forces ​in southern Lebanon overnight and that Israel had attacked in response.

Lebanon’s health ministry says 4,057 people have been killed in Israeli attacks since March 2, including medics, women and children.