Beirut was rocked on Wednesday by Israel's heaviest strikes killing 203 people including Ali Yusuf Harshi, top aide and nephew of Hezbollah chief Naim Qassem.
The attack has triggered outrage in Tehran, which branded the assault a "grave violation" of the ceasefire agreement brokered last month.
Iran's Deputy Foreign Minister Saeed Khatibzadeh warned that continued Israeli aggression could force Tehran into "full-scale defence." Foreign Minister Abbas Araghchi sharpened the message, telling Washington it must choose between honoring the truce or backing Israel's war. "The world sees the massacres in Lebanon. The ball is in the US court," he wrote on X.
The ceasefire, announced by Pakistan's Prime Minister Shehbaz Sharif, explicitly included Lebanon. But Israeli Prime Minister Benjamin Netanyahu dismissed that interpretation, insisting Lebanon was not part of the deal. "We will continue to strike Hezbollah wherever necessary until full security is restored," he said.
The killing of Harshi, a key Hezbollah strategist, is expected to escalate tensions further, with Iran and its allies accusing Israel of undermining fragile peace efforts in the region.