The talks come after Tehran announced that the strategic waterway had been closed in response to Israel’s military operations in Lebanon, warning that progress in negotiations could be limited if the conflict continues.

US President Donald Trump responded by threatening to impose transit tolls in the Strait of Hormuz if a comprehensive agreement with Iran is not reached within 60 days. Under the interim arrangement, commercial shipping is currently allowed to pass through the waterway without charges during the negotiation period.

Pakistan, which has been playing a mediating role, said technical-level discussions will begin Sunday with participation from Qatari mediators.

US Vice President JD Vance departed for Switzerland on Saturday, while Iranian state media showed members of Tehran’s delegation arriving in the country. The Iranian team is headed by Parliament Speaker Mohammad Bagher Qalibaf and includes Foreign Minister Abbas Araghchi, central bank officials and energy sector representatives.

Pakistan Prime Minister Shehbaz Sharif and Army Chief Field Marshal Asim Munir also travelled to Switzerland ahead of the talks.

Negotiations had originally been scheduled to start Friday but were postponed after intensified fighting in Lebanon prompted Iran to withdraw temporarily. US and regional officials said mediators later secured understandings aimed at reducing hostilities between Israel and the Iran-backed Hezbollah group.

Vance expressed optimism about progress on both Iran’s nuclear programme and efforts to secure a ceasefire in southern Lebanon. He confirmed that senior US negotiators Jared Kushner and Steve Witkoff were already in Switzerland.

However, Iranian Foreign Ministry spokesman Esmail Baghaei stressed that discussions on a final settlement would only proceed if commitments under the interim agreement are fully implemented.

The Strait of Hormuz emerged once again as a major point of contention. Iran’s military command claimed the waterway was closed due to what it described as a US failure to uphold commitments to help end regional fighting.

The United States rejected the claim, insisting that maritime traffic continued uninterrupted. US Central Command said 55 merchant vessels carrying more than 17 million barrels of oil transited the strait on Saturday under military monitoring.

The interim accord, signed earlier this week by Trump and Iranian President Masoud Pezeshkian, includes provisions for easing restrictions on Iranian oil exports and unfreezing billions of dollars in Iranian assets. Negotiators have been given 60 days to reach a broader nuclear agreement, although the timeline could be extended.

Meanwhile, violence continued in Lebanon. Israeli strikes on southern parts of the country killed at least 16 people, including two children, according to Lebanese media reports. Several people were also reported trapped beneath rubble in affected areas.

An Israeli military official said the army had received updated instructions to halt offensive operations while maintaining the right to respond to attacks. The official also confirmed that five Israeli soldiers had been killed in southern Lebanon during the past two days.

A Hezbollah official said Iran had informed the group that the Strait of Hormuz would remain closed until Israel publicly commits to a comprehensive ceasefire in Lebanon and ends military operations there. Hezbollah, the official said, would also observe a ceasefire if Israel does the same.

Despite diplomatic efforts, neither Israel nor Hezbollah is formally party to the US-Iran agreement.

The latest escalation has pushed the death toll from the Israel-Hezbollah conflict beyond 4,000, according to Lebanon’s Health Ministry.

Fresh US-backed discussions involving Lebanon and Israel are expected to take place in Washington next week as international efforts continue to secure a broader ceasefire.

Israeli Prime Minister Benjamin Netanyahu has maintained that Israeli forces will remain in southern Lebanon until all threats are eliminated, while Hezbollah insists it will not stop attacks without an Israeli withdrawal.

Residents on both sides of the border expressed mixed feelings about the prospects for peace, with some hoping for an end to the violence and others remaining skeptical that a lasting ceasefire can be achieved.