Escalating clashes between Israel and Hezbollah threatened to overshadow US President Joe Biden’s final appearance at the UN’s signature annual event as diplomats scrambled to avert an all-out regional war. According to , the gathering of dozens of world leaders, the high point of the diplomatic calendar, comes a day after Israeli air strikes on Lebanon killed more than 490 people, according to local authorities. As world leaders gathered in Manhattan on Monday for the annual flurry of speeches and face-to-face diplomacy, UN Security Council member France called for an emergency meeting on the crisis engulfing the Middle East. Israel’s closest ally, the United States, again warned against a full-blown ground invasion of Lebanon, with a senior US official promising to bring “concrete” ideas for de-escalation to the UN this week. It is unclear what progress can be made to defuse the situation in Lebanon as efforts to broker a ceasefire in Gaza, which Israel has relentlessly pounded since October 2023, have come to nothing. “Gaza, Ukraine and Sudan will be the dominant issues,” said Richard Gowan of the International Crisis Group think tank, adding he expected many leaders to “warn that the UN will become irrelevant globally if it cannot help make peace”.