The high-level General Debate, which begins on Tuesday following two weeks of meetings, is the most widely watched event in the UN’s annual calendar.

It provides world leaders and heads of state the opportunity to lay out their priorities for the coming year, urge cooperation on pressing issues, and often, call out their adversaries.

“It is a one-of-a-kind moment each year for leaders from every corner of the globe to not only assess the state of the world but to act for the common good,” UN Secretary-General Antonio Guterres told reporters last week. “And action is what the world needs now.”

This year’s General Debate is being held under the theme, “Rebuilding trust and reigniting global solidarity: Accelerating action on the 2030 Agenda and its Sustainable Development Goals towards peace, prosperity, progress and sustainability for all”.

A series of bilateral discussions will also be held on the sidelines of the event.

Here’s all you need to know:

New page dedicated to the United Nations General Assembly High-level Week has just been launched!

One-stop-shop with lots of useful information on key events during the high-level week of #UNGA78: https://t.co/oZ6fCJVHZl

— United Nations Geneva (@UNGeneva) August 28, 2023

What is the overall role of the UN General Assembly?

The 193-member UN General Assembly debates matters of human rights, international law and cooperation in “economic, social, cultural, educational, and health fields”. It has the ability to pass resolutions and declarations meant to set out the guiding principles of the organisation.

According to the UN Charter, the body is also charged with addressing matters of international peace and security not currently being addressed by the UN Security Council (UNSC).

The UNGA approves the UN’s sprawling annual budget and one of its six main committees directly oversees the funding of peacekeeping missions around the world.

Who will speak at the General Debate?

The UNGA president typically delivers the first speech of the General Debate. This session’s leader, Dennis Francis from Trinidad and Tobago, has said (PDF) that he wants to prioritise greater multilateralism and equal opportunity during his tenure.

Brazil then traditionally delivers the first country speech, with President Luiz Inacio Lula da Silva expected to make climate change a centrepiece of his address. Lula, who took office in January, has vowed to re-establish Brazil as a global leader in the environment and bolster the protection of the critical Amazon rainforest after years of destruction.

The United States, as the host country, will then follow Brazil, with US President Joe Biden set to deliver an address to the General Assembly on Tuesday seeking to assert Washington’s role as a global leader.

From there, “the order of speakers then follows a complex algorithm reflecting level of representation, geographical balance, the order in which the request to speak was recorded, and other considerations”, the UN says on its website.

Which other leaders will be there?

About 150 leaders are expected to attend the high-level talks, Linda Thomas-Greenfield, the US ambassador to the UN, said late last week.

Among others, Ukrainian President Volodymyr Zelenskyy will be there, as will Israeli Prime Minister Benjamin Netanyahu. Both are expected to address the General Assembly and hold talks with Biden on the sidelines of the event.

The Reuters news agency also reported last week that Zelenskyy will speak on Wednesday at a UN Security Council meeting on Ukraine, which “could place him at the same table as Russian Foreign Minister Sergey Lavrov” amid Russia’s ongoing military offensive.

Who won’t be there?

Biden will be the only top leader of the UN Security Council’s five permanent, veto-wielding countries – the US, China, Russia, France and the United Kingdom – to attend the high-level week, media outlets have reported.

Rishi Sunak will be the first British prime minister in more than a decade to skip the event, saying his busy schedule prevents him from going to New York. French President Emmanuel Macron will also miss the event, citing scheduling conflicts.

It remains unclear which Chinese official will attend the summit after the Wall Street Journal reported in early September that Beijing planned to dispatch Vice President Han Zheng instead of sending Foreign Minister Wang Yi on a broader US trip as previously signalled.

What topics will be discussed?

Given the diversity of speakers, the General Debate usually covers a range of issues of regional and global interest.

Last year’s predominant themes included efforts to recover from the COVID-19 pandemic, Russia’s invasion of Ukraine, and climate change – all of which are expected to again figure prominently during this year’s event.

Speaking to reporters in late August, the US envoy, Thomas-Greenfield, said she expects most Western countries to exert “intense pressure” on Russia to withdraw troops from neighbouring Ukraine.

The invasion has renewed calls to expand decision-making power on the 15-member UN Security Council, where Russia is among the five permanent members – alongside China, France, the United Kingdom and the US – who wield veto power.

Concerns over China, maritime security in the Pacific, supply-chain disruptions and human rights are also likely to emerge, particularly as some observers have questioned Beijing’s growing influence at the UN.

Recent coups in Africa, notably in Niger, may also receive heightened attention, as will ongoing conflicts in Sudan and Ethiopia. Meanwhile, ongoing humanitarian crises in places such as Afghanistan, the Horn of Africa and Latin America – and their role in a global migration crisis – may also feature prominently.

Meanwhile, the General Debate comes two months before the United Nations’ climate summit, COP28, will be held in Dubai and Guterres, the UN secretary-general, will host a Climate Ambition Summit on the sidelines of this week’s event in New York.

“My appeal to world leaders will be clear: This is not the time for posturing or positioning. This is not the time for indifference or indecision. This is a time to come together for real, practical solutions,” Guterres said during a news conference on September 13.

What’s behind this year’s theme?

Themes set out by UNGA presidents are traditionally broad – and this year’s is no exception.

Francis said in a June letter to his predecessor that the 2023 theme “encompasses the recognition that we are at a crossroads in history and that the path ahead will be decisive in determining not only our future, but that of generations to come”.

He called for a renewed commitment to multilateralism and urged UN member states to see how they can “undertake coordinated purposive action” to promote peace and security, fight climate change, and promote human rights.

The theme also stresses the need to accelerate efforts to meet the UN’s Sustainable Development Goals.

What are the Sustainable Development Goals?

The UN has described the Sustainable Development Goals as “an urgent call for action” between nations to address poverty, hunger and other global issues.

They were laid out in the so-called “2030 Agenda for Sustainable Development”, which was adopted in 2015 and provides a blueprint for achieving several benchmarks by 2030.

The list includes 17 goals, including ensuring quality education, providing clean water and sanitation, and taking urgent action to tackle the climate crisis.

How can I watch the General Debate?

The General Debate will be streamed live on UN Web TV, here.