JERUSALEM (AP) — Talks between the U.S. and Iran were called off on Friday after intense fighting between Israel and Hezbollah in southern Lebanon, three officials said, raising questions about a nascent agreement to end the war in Iran.Iranian officials didn’t travel as planned to Switzerland, insisting that the fighting in Lebanon must stop before the talks can take place, according to the officials, who spoke on condition of anonymity to discuss the ongoing mediation to try to get the talks rescheduled. U.S. Vice President JD Vance also canceled his trip.Israel’s military struck targets in southern and eastern Lebanon overnight, and Hezbollah reported intense fighting. Lebanon’s Health Ministry said at least 21 people were killed, and Israel said four soldiers died.The conflict between Israel and Iran-backed Hezbollah is the most precarious part of the Iran deal. Neither Israel nor the militant group signed the agreement — but it is supposed to end their fighting, and Iran has signaled its willingness to risk renewed war in the region for the sake of its interests in Lebanon and its most important regional ally.Mediators are now scrambling to reschedule the meetings, which were supposed to begin addressing how to restrict Iran’s nuclear program — the core issue over which Israel and the U.S. went to war on Feb. 28.The talks are also supposed to bring about a permanent end to the conflict. The interim deal has already reopened the Strait of Hormuz to international shipping, after Iranian attacks and threats all but stopped the flow of oil and natural gas through the waterway. A new Iranian authority charged with overseeing the strait issued guidance Friday calling on ships to register with it even as transits are currently free — signaling Tehran’s intent to likely start charging.Talks planned for Friday in Switzerland between Iran and the United States, which Vice President JD Vance had been scheduled to attend, found themselves postponed as the fighting intensified.AP Photo/Manuel Balce CenetaThe Fighting In Lebanon Could Unravel The DealThe Israeli military said strikes were ongoing on Friday after four of its soldiers, including a lieutenant colonel, were killed in an attack on a tank in a village near the southern Lebanese city of Nabatiyeh. An explosive drone attack wounded another five, it added.Israel then launched multiple strikes against “Hezbollah infrastructure sites” in Nabatiyeh and other areas, according to a military statement, which accused the militant group of “blatant ceasefire violations.”Later, the military said it also struck targets in the Beqaa Valley in eastern Lebanon, with Lebanese media saying the village of Douris was hit.“Israel will not tolerate attacks on our soldiers or on our territory, and it will exact a very heavy price from Hezbollah for these attacks,” Netanyahu said in a statement Friday.Hezbollah acknowledged targeting Israeli tanks and said its attacks were in response to what it called Israel’s own violation of the ceasefire. It said the attacks came after Israeli forces attempted to reach the northern side of Ali al-Taher hilltop, a strategic point that overlooks Nabatiyeh and that Israeli troops have been trying to capture.In southern Lebanon, many were forced to flee their villages due to the Israeli attacks.“The situation is lawless, we couldn’t stay,” said Mustafa Zain, who had his six daughters in a pickup truck as he was leaving Akaar through Tyre.Smoke rises to the sky in an area near Beaufort Castle following an Israeli military strike in southern Lebanon as seen from northern Israel, on June 19, 2026.AP Photo/Leo CorreaThe fighting threatens to unravel the newly signed deal. Beyond ending the hostilities in Lebanon, the agreement calls for ensuring Lebanon’s “territorial integrity and sovereignty.”It does not say whether that means Israel would withdraw from the large swaths of southern Lebanon it has occupied since Hezbollah joined the war in its early days by firing rockets and drones at northern Israel.Iran has insisted Israel pull back, while Israeli Prime Minister Benjamin Netanyahu said Thursday that forces would remain in a “security zone” of southern Lebanon as long as “Israel’s security needs require it.”Israel’s actions in Lebanon have created a rift between Israel and the U.S., with Trump becoming increasingly critical of his close ally Netanyahu. Netanyahu is also facing increasing criticism at home — and from other quarters.Israeli Prime Minister Benjamin Netanyahu, who faces elections later this year, has refused to withdraw, saying Israeli forces will remain in Lebanon until the threat from Hezbollah has been eliminated.Ronen Zvulun, Pool Photo via APTalks In Switzerland Were PostponedTehran is insisting that Israel’s attacks in Lebanon cease before they send a delegation to Switzerland, according to the officials.The White House, however, blamed logistical issues when Vance put off his trip.Two other regional officials, similarly speaking on condition of anonymity for the same reason, described Pakistan as being “stunned” by Iran’s decision not to go to the talks.Much Remains To Be ResolvedThe discussions in Switzerland are expected to focus on Iran’s nuclear program. Tehran maintains it is peaceful, though it has highly enriched uranium that could be used to build multiple atomic bombs, should it choose to do so, according to the International Atomic Energy Agency.Those talks are expected to be extremely difficult. The 2015 nuclear deal, which Trump scrapped during his first term, took more than 18 months to negotiate.The interim deal gives negotiators 60 days to come up with a nuclear agreement but that can be extended. It outlines lucrative incentives if Iran does reach a new agreement, including the eventual lifting of all international sanctions and a $300 billion fund for postwar reconstruction.Already Iran has won some concessions. Following the signing of the interim deal, the U.S. lifted its blockade of Iran’s ports and is allowing it to sell its oil freely. The deal also calls for Iran’s assets to be unfrozen — though it’s not clear how quickly.Oil tankers began freely moving through the Strait of Hormuz this week after months of being unable to use the critical channel. More than 12.5 million barrels of oil were shipped through the waterway on Wednesday night, the U.S. said.Still, it is expected to take weeks or months for the normal flow of oil and gas to resume, even if traffic fully resumes in the strait.___Gambrell reported from Dubai, United Arab Emirates, and Rising from Bangkok. Associated Press journalists Bassem Mroue in Beirut, Samy Magdy in Cairo, Malak Harb in Tyre, Lebanon, Munir Ahmed in Islamabad and Areej Hazboun in Jerusalem contributed to this story.