Every September, world leaders gather at the United Nations headquarters in New York for the UN General Assembly (UNGA) -- the world's biggest diplomatic meeting. Countries debate, make statements, and vote on the biggest global issues, from climate change to peace and security. This year (2025) it began on September 9 with organisational work and election of the new president. All 193 UN member states can speak, plus observers like Palestine and the Holy See (Vatican). By tradition, Brazil speaks first and the United States second.