ZURICH/DUBAI/WASHINGTON: US and Iranian negotiators were set to begin talks in Switzerland on Sunday aimed at advancing a fragile ceasefire and laying the groundwork for a broader agreement on Iran’s nuclear program and regional security, even as the two sides clashed over Tehran’s claim that it had closed the strategic Strait of Hormuz.

Iran to Send Delegation to Switzerland to Follow Up on U.S.-Iran Agreement, State Media Reports. Vance Says U.S. Officials on Ground for Iran Talks; No Evidence Tehran Is Closing…

Iran said Saturday it was closing the Strait of Hormuz again over Israeli attacks in Lebanon, jolting a fragile US-Iran agreement just as negotiators headed to Switzerland to try…