World Leaders Gather at UN as Wars, AI and Global Governance Dominate Agenda
NEW YORK, September 22, 2026 — World leaders have gathered at United Nations headquarters in New York for the opening of the high-level debate of the 81st UN General Assembly, with war, international security, artificial intelligence, climate change and the future of multilateral cooperation dominating the agenda.
Nearly 130 heads of state and government are expected to address the General Assembly during the high-level week, which runs from September 22 to September 28. The official theme is “Restoring trust, managing transformation: a United Nations that delivers for all.”
The meeting comes at a particularly tense moment in international affairs, with conflicts in the Middle East and Ukraine among the major issues expected to feature in leaders’ speeches and bilateral discussions.
Trump puts Iran war at centre of speech
US President Donald Trump addressed the General Assembly on Tuesday, using his speech to defend the US decision to go to war with Iran.
Trump argued that American military action had prevented Iran from obtaining a nuclear weapon and warned that the United States could take further military action if Tehran does not agree to a deal. Reuters reported that Trump warned he could “annihilate” Iran if an agreement is not reached.
The speech placed the Iran conflict at the centre of this year’s diplomatic gathering and is likely to influence discussions between the United States and other governments throughout the week.
Guterres delivers final UNGA address
UN Secretary-General António Guterres, whose second term ends on December 31, delivered what is expected to be his final General Assembly address.
Guterres warned that divisions between countries are deepening and called for greater international cooperation. He highlighted wars, climate change, inequality and the rapid development of artificial intelligence as interconnected challenges requiring international responses.
He also called for stronger international governance of artificial intelligence and reform of UN institutions, including the Security Council.
Macron, Erdoğan and Zelenskyy among key figures
French President Emmanuel Macron, Turkish President Recep Tayyip Erdoğan and Ukrainian President Volodymyr Zelenskyy are among the leaders taking part in the opening day’s diplomacy. UK Prime Minister Andy Burnham is also scheduled to address the General Assembly later Tuesday.
Zelenskyy’s participation comes as the war in Ukraine remains a central issue for European governments and their discussions with the United States and other international partners.
Gaza and Middle East tensions
The Middle East is expected to remain one of the most difficult issues confronting diplomats in New York.
The conflict involving Israel and the Palestinians, alongside the wider regional confrontation involving Iran, is expected to feature prominently in speeches and private meetings.
Israeli Prime Minister Benjamin Netanyahu is scheduled to address the General Assembly on Thursday, while Iranian President Masoud Pezeshkian is due to speak on Wednesday.
Palestinian President Mahmoud Abbas, meanwhile, is expected to address the assembly by prerecorded video after the United States denied visas to Palestinian officials for the meeting, according to Al Jazeera.
Climate change and AI also on agenda,
The General Assembly is not focused solely on current conflicts. Climate change, development, pandemic preparedness and artificial intelligence are also major elements of this year’s programme.
High-level meetings scheduled during the week will address the right to development, rising sea levels, pandemic prevention and preparedness, and other global challenges.
AI has become an increasingly prominent diplomatic issue, with Guterres calling for international rules and oversight as governments attempt to address both the opportunities and risks created by rapidly developing AI systems.
A changing United Nations
This year’s gathering also comes as the UN prepares for a change in leadership.
Guterres will leave office at the end of 2026 after two five-year terms. The process of selecting his successor is already under way, although the next secretary-general is not expected to be chosen during this week’s General Assembly meetings.
The 2026 gathering therefore represents both a major diplomatic forum for addressing immediate international crises and an important moment for discussions about the future direction of the United Nations.
The high-level General Assembly debate continues through September 26 and resumes on September 28.