The second day of the United Nations General Assembly is set to be dominated by three major global issues: the war in Iran, the rapid development of artificial intelligence and the worsening climate crisis, as world leaders gather in New York amid growing international tensions and uncertainty.

US President Donald Trump was among the first leaders to address the gathering, using his speech to highlight the conflict with Iran and signal that Washington faces a major decision over how to proceed.

Trump said he had a “big decision” to make regarding Iran, framing the choice as either reaching a deal or taking much more severe action against the country. His remarks are expected to add further pressure to international diplomatic efforts surrounding the conflict.

The Iran war is likely to remain one of the central issues throughout the General Assembly, with governments expected to discuss the conflict's regional and international consequences, including its impact on security, diplomacy, energy markets and civilian populations.

Beyond the immediate conflict, artificial intelligence is also expected to feature prominently in discussions among world leaders. The rapid expansion of AI has raised questions about its economic and social impact, as well as concerns over security, regulation, misinformation and the future of work.

Governments are increasingly seeking international cooperation over how AI should be developed and governed, particularly as technological advances continue to outpace existing regulatory frameworks.

Climate change will form another major part of the debate. World leaders are expected to discuss the continuing environmental crisis, including rising temperatures, extreme weather events, emissions reductions and the need for greater international cooperation on climate policy and financing.

The discussions come as the international community faces multiple overlapping challenges. Wars and political tensions are unfolding alongside environmental pressures and what many governments and institutions regard as a period of unprecedented technological change.

The General Assembly therefore provides a rare forum in which leaders can address these issues collectively, although major differences remain over how the international community should respond.

With conflicts, climate change and artificial intelligence competing for attention, the second day of the UN gathering is expected to offer a broad picture of the challenges facing the international system — and the difficulties involved in finding common ground among nations.