The first round of negotiations between the United States and Iran on a permanent peace settlement and Tehran’s nuclear programme was postponed on Friday, after Iran declined to dispatch its delegation to the Swiss resort of Bürgenstock. The White House confirmed that Vice President JD Vance, who was to lead the American team, delayed his departure, attributing the move to logistical challenges. Switzerland’s foreign ministry announced the postponement without specifying a reason, while stating it remained ready to facilitate the talks. The delay came as Israeli forces struck targets across southern and eastern Lebanon overnight, killing at least 18 people according to Lebanon’s Health Ministry, and Hezbollah reported intense fighting that left four Israeli soldiers dead.

Iranian officials, speaking on condition of anonymity to the Associated Press, said the Lebanon question is “central” and that the Israeli strikes constitute a violation of the first clause of the interim memorandum signed on Wednesday, which calls for an immediate and permanent cessation of hostilities on all fronts, including Lebanon. Tehran’s chief negotiator, Parliament Speaker Mohammad Bagher Ghalibaf, warned that Iran’s “red lines” would not be crossed and that its “finger remains on the trigger.” From Jerusalem, Prime Minister Benjamin Netanyahu declared Israeli forces would remain in a “security zone” in southern Lebanon as long as necessary, while far-right National Security Minister Itamar Ben Gvir wrote on social media that “all of Lebanon must burn.” In Washington, President Donald Trump publicly urged Netanyahu to be “more responsible with respect to Lebanon,” and Vice President Vance told the New York Times that “you can’t just kill your way out of solving every single national security problem,” signalling a rare rift between the allies.

The postponement places immediate strain on the interim deal, which had already reopened the Strait of Hormuz to international shipping. Maritime tracking data from AXSMarine showed 25 commercial vessels transited the strait on Thursday, the highest number since mid-April, but traffic appeared to dip early Friday amid the uncertainty. The agreement’s 60-day negotiation window, intended to address sanctions relief, the lifting of the US naval blockade, and verifiable restrictions on Iran’s uranium enrichment, now faces delay. Mediators from Pakistan and Qatar are working to reschedule the talks, while the renewed violence has triggered further displacement in southern Lebanon, where many families fled their villages.

The war began on 28 February with US-Israeli strikes that killed Iran’s supreme leader, drawing Hezbollah into the conflict. The interim deal, signed by Trump and Iranian President Masoud Pezeshkian, committed both sides to a permanent ceasefire and the eventual removal of the blockade in exchange for Iran’s pledge not to develop nuclear weapons and to eliminate enriched uranium under IAEA supervision. Israel and Hezbollah are not signatories, but the text explicitly covers Lebanon. The dossier now awaits a new date for negotiations, with Swiss logistical preparations remaining in place and mediators seeking to secure Iran’s return to the table.