Top US and Iranian officials began talks in Switzerland on Sunday, in a renewed push to turn a fragile ceasefire into a lasting peace after Israeli attacks in Lebanon threatened to derail the process.
It marks only the second time US and Iranian officials have sat down together since the Islamabad talks in April though Sunday's session, like that one, opened indirectly rather than face-to-face.
The talks came as Iran said it had reimposed a blockade of the Strait of Hormuz, a move that injected fresh economic uncertainty into the negotiations, though the US military and monitors said the situation was unclear, and that early traffic reports showed little immediate change.
The talks, in the resort of Burgenstock, opened with an indirect meeting between Swiss Federal Councillor Ignazio Cassis and Iranian Foreign Minister Abbas Araghchi, the Federal Department of Foreign Affairs said.
“This meeting forms part of the discussions between the United States and Iran on the implementation of the memorandum of understanding signed between the two countries,” it said. “The talks focused primarily on how to translate this agreement into concrete and operational steps.”
Since 1980, Switzerland has acted as the protecting power for US interests in Iran, a role that has kept a rare diplomatic channel open even during periods of confrontation.
A trilateral meeting between the US, Iran and Qatar was also reportedly held to discuss frozen funds and Israel's attacks on Lebanon, Iranian state broadcaster reported.
'Expectations high'
“In the current context, the simple fact that the parties are present, that they are talking to each other and that they are continuing this dialogue already constitutes a significant contribution to the implementation of the agreement,” a Swiss representative said.
“This shows that diplomatic channels remain open and that the patient work of diplomacy can foster trust, even in complex situations,” the representative said. “We know that implementing such an agreement presents a significant challenge, particularly when deadlines are tight and expectations are high. It is precisely at such times that diplomacy, discretion and trust are essential.”
US Vice President JD Vance landed at Emmen Air Base in the morning before heading to Burgenstock, where American, Iranian, Qatari and Pakistani officials gathered for the first structured sessions under the new process.
Mr Vance was leading an American delegation which includes White House envoys Steve Witkoff and Jared Kushner, while Iran's was headed by Mr Araghchi and parliamentary Speaker Mohammad Bagher Ghalibaf.
Iranian Foreign Ministry spokesman Esmaeil Baghaei said the talks would last only one day and focus strictly on enacting the agreement, not broader political issues, citing Washington’s failure to guarantee a ceasefire in Lebanon.
Qatar's Ministry of Foreign Affairs said the “Lake Lucerne Summit” and the first meeting of the High-Level Committee had formally begun, with representatives from the US, Iran, Qatar and Pakistan taking part as co-mediators.
It said the process would include technical and specialised working groups, along with dedicated follow-up groups, to negotiate terms and monitor implementation of the agreement and progress towards a final deal – a structure it described as designed to ensure “good faith” negotiations and a “comprehensive and sustainable agreement”.
Qatar said the aim is to keep negotiations on track through technical workstreams, while Pakistan is playing a co-mediating role alongside Doha.
Speaking at the summit, Mr Vance said Mr Trump had asked to "turn a new leaf" and to "extend an outstretched hand" to Iran. "What today really represents is the beginning of a technical negotiation... [that's] going to allow us to sit together, as teams, for the first time really in history, to figure out what matters most to the respective parties, to settle those issues and get to a better tomorrow," he added.
"The question is whether we can change relations in the Middle East permanently," he said.
International Atomic Energy Agency chief Rafael Grossi also met the Swiss Foreign Minister Ignazio Cassis in Burgenstock, where they discussed Iran’s nuclear programme and the agency’s role in monitoring developments.
Mr Grossi said on X that they reviewed “recent developments regarding Iran, the path ahead and the important role” of the IAEA, adding that “at this critical moment, it’s important to give diplomacy every opportunity to succeed”.
He thanked Switzerland for hosting and supporting multilateral diplomacy. The Swiss government said the talks are now moving into a structured implementation phase, with technical groups given the task of turning broad commitments into verifiable steps.
The diplomatic push comes as the wider region remains on edge, with fighting continuing in Lebanon and Gaza despite ceasefire claims, and continued Israeli strikes reported despite ceasefires being repeatedly announced – more than a million people have been displaced since Israel's invasion in March.
Officials in Tehran have said that progress on the deal is tied to full compliance across all agreed fronts, warning that partial implementation would unravel the framework.
Iran’s Islamic Revolutionary Guard Corps warned that ships could be at risk if they approach the Strait of Hormuz, where they said no new transit permits were being issued, although US officials disputed that the strait was actually closed and said dozens of merchant vessels were continuing to pass through.
In Israel, a new poll shows deep scepticism over the outcome of the recent conflict and the US–Iran agreement. The Agam Institute–Hebrew University survey found 92.1 per cent of respondents believe Iran emerged as the winner, while 82.9 per cent said Israel’s long-term security had been weakened.
The same poll found 72.5 per cent reject Prime Minister Benjamin Netanyahu’s claim of strategic gains, and 87.8 per cent said Israel had failed or only partially met its objectives. Nearly half said they would support renewed large-scale action against Hezbollah even at the risk of confrontation with US President Donald Trump.
As talks settle into their first working sessions, mediators are trying to lock in a process that moves beyond political declarations into monitored implementation. Whether that structure can hold now depends on whether the parties can keep co-operation intact while conflicts in Lebanon and Gaza remain active.
