Talks between Iran and the US were postponed on Friday in Switzerland, delaying what was supposed to be the opening round of negotiations towards a permanent peace and nuclear deal.The delay appears to center on a new escalation between Israel and Iran-backed Hezbollah militants in southern Lebanon, a troubling development that threatens the fresh interim deal signed by President Trump and Iran just days ago. Tehran has insisted that a ceasefire in Lebanon is part of the interim deal, meaning the Israel-Hezbollah front could derail the US-Iran diplomatic path to a sustained reopening of the Strait of Hormuz.The Financial Times provided more details on the overnight development:Talks between Iran and the US in Switzerland were postponed due to Israel launching a wave of deadly air strikes on southern Lebanon, according to three people familiar with the matter.Iran did not send a delegation to Switzerland for the nuclear talks because of the attacks, the people said. The interim agreement signed by the US and Iran on Wednesday stipulates the "immediate and permanent termination" of fighting, including in Lebanon.A diplomat familiar with the Switzerland talks told the outlet:The Iranians have asked for guarantees that hostilities in Lebanon will end, as outlined in the signed agreement, and mediators are currently working to resolve the issue.According to other FT sources, Iran's position is effectively "no Lebanon, no deal," arguing that it has restrained Hezbollah while Washington has failed to restrain Israel.Israeli airstrikes across more than 10 villages in southern Lebanon killed 18 people and wounded 33, according to Lebanon's health ministry.⭕️WATCH: A Hezbollah launcher firing rockets toward IDF soldiers