The United States expects negotiations with Iran to continue overnight in Switzerland on Sunday as both sides attempt to advance a fragile diplomatic process aimed at easing tensions over nuclear and regional security issues, according to a U.S. official.
The talks got off to a rocky start, with the Iranian delegation briefly walking out of the opening session in protest against U.S. President Donald Trump’s threats of military action over Iran’s support for Hezbollah in Lebanon. Despite the disruption, a U.S. diplomat at the venue said the situation later stabilized and Iranian officials returned to the negotiating table for what were described as detailed discussions on core elements of a nuclear-related agreement.
“The talks included clarifying some confusing messages from Iran regarding the Strait of Hormuz and establishing deconfliction mechanisms to ensure the waterway remains fully open,” the diplomat said, according to AFP on Monday, June 22, 2026.
However, the negotiations remained strained by deep disagreements on key issues and renewed concerns over fighting in Lebanon, with Washington and Tehran continuing to exchange threats alongside the diplomatic engagement.
Trump has repeatedly warned that the United States would strike Iran if Tehran did not rein in its allies in Lebanon, while Iranian officials responded with their own warnings. “They should be careful with their statements. Our armed forces are ready to respond in different ways. Whatever they say, we are the ones who will act,” Iran’s chief negotiator Mohammad Bagher Ghalibaf said.
A state-run Iranian television report said nuclear issues were not addressed during the first 80-minute round of talks on Sunday, with discussions instead focusing on implementing a memorandum of understanding between Washington and Tehran and the situation in Lebanon. The agreement is intended to reduce hostilities and establish a framework for broader negotiations.
U.S. Vice President JD Vance, speaking alongside U.S. negotiators Jared Kushner and Steve Witkoff at the Burgenstock resort near Lake Lucerne, praised the meeting as an important diplomatic moment. “The question before us now is how much more can we achieve together?” Vance said. “Can we start a new chapter? Can we permanently change relations in the Middle East? Or do we go back to doing things the old way, which is not our preference, but certainly something that is possible.”
Iranian President Masoud Pezeshkian said Tehran would not abandon its right to enrich uranium, while reiterating that the country does not seek nuclear weapons. “We can also state in writing that we have no intention of making a bomb,” he said, according to Iranian state media.
The negotiations come as both sides seek to manage multiple flashpoints across the region, including Lebanon, where intermittent clashes have continued to undermine efforts to stabilize the ceasefire framework underpinning the broader U.S.-Iran diplomatic initiative.
