France, Sept. 22 -- Some 130 heads of state and government are expected to address the assembly, as leaders confront conflicts in Iran, Gaza, Ukraine, Sudan, the Democratic Republic of Congo and Myanmar - and the persistent question of what the UN can realistically do to help end them.

Climate shocks, widening inequality and disruption to global trade will also be high on the agenda, as blocked shipping routes and strained supply chains push up prices and weigh on growth.

At the same time, the rapid development of artificial intelligence has emerged as a major concern, amid warnings over the lack of international safeguards for increasingly powerful technology.

The gathering comes at a difficult moment for the United Nations itself. No...