NAIROBI, Kenya, Mar 1 — United Nations Secretary General António Guterres has called for an immediate cessation of hostilities following a dramatic escalation of military confrontation involving the United States, Israel and Iran, warning that the world stands at a dangerous crossroads.In an urgent appeal to the UN Security Council on Saturday, Guterres condemned the exchange of attacks, saying the use of force risks undermining global peace and security.“I condemn today’s military escalation in the Middle East. The use of force by the United States and Israel against Iran, and the subsequent retaliation by Iran across the region, undermine international peace and security,” he said in an address to the Council in New York.The UN chief reminded all member states of their obligations under international law, particularly the UN Charter, which prohibits “the threat or use of force against the territorial integrity or political independence of any state.”Guterres structured his remarks around “the principles, the facts, and the way out,” as tensions surged following large-scale military strikes involving the United States, Israel and Iran.Regional conflict He called for urgent de-escalation to prevent a wider regional war.“I call for an immediate cessation of hostilities and de-escalation. Failing to do so risks a wider regional conflict with grave consequences for civilians and regional stability,” he said.“Let us act responsibly and together to pull the region and our world back from the brink. Everything must be done to prevent a further escalation.”He strongly encouraged all parties to return immediately to the negotiating table, reiterating that there is no viable alternative to the peaceful settlement of disputes.“Lasting peace can only be achieved through peaceful means, including genuine dialogue and negotiations,” he stressed.The escalation comes even as Iran confirmed the killing of its Supreme Leader, Ali Khamenei, during the first day of massive US and Israeli air strikes on Iranian targets.President Donald Trump announced Khamenei’s death, which was later confirmed by Iranian state television.Khamenei’s deathKhamenei, 86, had ruled Iran for more than three decades, making him one of the world’s longest-serving leaders. Since the 1979 Islamic Revolution, Iran has had only two supreme leaders.The position holds sweeping powers, with authority over the armed forces, including the elite Revolutionary Guards, and the ability to veto public policy decisions.His death marks a historic turning point for Iran and could reshape the political landscape of the region.Iran has launched retaliatory strikes across the region, including reported missile attacks targeting US military installations. Huge plumes of smoke were seen rising near the headquarters of the US Navy’s Fifth Fleet in Manama, Bahrain, though the extent of damage remains unclear.Qatar’s defence ministry said it intercepted several missiles aimed at the al-Udeid air base, the largest American military installation in the region.Iran’s Revolutionary Guard Corps said it was targeting U.S. bases and assets as part of “Operation Truthful Promise 4,” describing it as retaliation for the strikes launched earlier by US and Israeli forces.Air raid sirens were also heard across Israel following reports of incoming Iranian missile barrages.The United Arab Emirates confirmed that falling debris from intercepted missiles caused material damage in a residential area and resulted in the death of one civilian of Asian nationality.AU expresses concernIn Addis Ababa, the African Union Commission expressed grave concern over the escalating confrontation. The Chairperson of the Commission, Mahmoud Ali Youssouf, warned that the intensifying hostilities pose serious threats to global stability, with ripple effects on energy markets, food security and economic resilience, particularly in Africa.He urged restraint and renewed diplomatic engagement, including ongoing mediation efforts facilitated by Oman.“Sustainable peace can only be achieved through diplomacy, not through force,” he said.The confrontation has already disrupted regional air travel, with several international airlines suspending operations amid airspace closures. Markets have shown signs of volatility as fears grow over oil supply disruptions and broader instability.Guterres reiterated that the UN Charter remains the foundation for maintaining international peace and security.“These actions carry the risk of igniting a chain of events that no one can control in the most volatile region of the world,” he warned.