US Vice President JD Vance has arrived at a resort overlooking Lake Lucerne in Switzerland for talks with senior Iranian officials over ways of implementing a preliminary accord to end the U.S.-Iran war and keep the Strait of Hormuz open. The talks are co-mediated by Qatar and Pakistan at the Bürgenstock resort near the city of Lucerne. A U.S. team led by Vance, including Jared Kushner and Steve Witkoff, is to meet with Iranian negotiators led by parliamentary Speaker Mohammad Bagher Qalibaf and Foreign Minister Abbas Araghchi. Pakistani envoys are also in place, as well as Qatari mediators, for the technical-level discussions to end the conflict that began in late February. Vance said he was optimistic about making progress in talks about Iran’s nuclear program and a ceasefire in southern Lebanon. On the eve of the talks, Tehran announced it has closed the Strait of Hormuz again over Israel’s ongoing military campaign in Lebanon. The interim deal between the US and Iran is meant to stop fighting on all fronts, including Lebanon, as well as calling for billions of dollars of Iran’s assets to be unfrozen. US President Donald Trump has threatened to impose American tolls in the strait if a final deal with Iran isn’t reached in 60 days. The interim agreement calls for toll-free travel for 60 days in the waterway that is vital for the world's oil supply.