The United Nations General Assembly opens its 80th session on Tuesday, bringing world leaders to New York for a week of speeches expected to focus on the wars in Gaza and Ukraine, Iran’s nuclear program, climate change and other global crises.

Who speaks when?

The United Nations was formed in 1945 with 51 original members and has since grown to 193 members. Leaders of two non-member observer states, known at the U.N. as the Holy See and the State of Palestine, and an observer member, the European Union, can also speak.

It is tradition for Brazil to always be the first member state to speak. This is because in the early years of the world body Brazil stepped up to speak first when other countries were reluctant to do so, say U.N. officials.

As host to the U.N. headquarters in New York, the United States is the second country to address the General Assembly.