United Nations Secretary-General Antonio Guterres has called for major reforms to the institutions that shape global security and finance, arguing that today's increasingly multipolar world cannot be effectively governed through structures designed for the realities of 1945.

Addressing leaders at the 18th BRICS Summit in New Delhi on September 13, Guterres said multipolarity could bring greater balance to international relations, but warned that this would depend on reforms to institutions including the UN Security Council and the Bretton Woods system.

On financing, the Secretary-General said developing countries are mobilising more domestic resources but still require substantially greater international support to achieve the Sustainable Development Goals, calling for stronger representation of developing countries in the global financial system.

Guterres also focused on artificial intelligence, saying the technology could accelerate decades of development progress, while warning that AI capabilities remain concentrated in a small number of companies and countries, risking wider gaps in income, opportunity and security.

On climate change, Guterres pointed to intensifying heat, floods, wildfires and glacier loss and warned that the world is approaching an overshoot of the 1.5C temperature threshold, calling for faster movement away from fossil fuels.

On peace and security, Guterres referred to conflicts in Gaza, the wider Middle East, Ukraine and Sudan and urged countries to uphold the UN Charter and international law, including sovereignty, territorial integrity and peaceful settlement of disputes.