G20 countries, as the world’s biggest economies, "need to look seriously into reform of global financial institutions, rules and frameworks, to adapt them to today’s realities and more effectively enable developing countries to access the resources they need to invest in the (UN) Sustainable Development Goals (SDGs)", he said.

"They account for 80 per cent" of the world’s greenhouse gas emissions and "as climate chaos gathers pace, the world is looking to them", he said.

"They need to step up, accelerating their reduction of emissions," he added.

After the G20 Summit hosted by India on September 9 and 10 that will bring together the leaders of the members of the group of major emerging and developing countries as well as those of nine invitees, the G77 summit in Cuba is on Guterres’s itinerary.

He called the G77, that includes China, "the voice of the Global South – the largest group of countries on the international stage” and said: "I will focus on getting the 2030 (UN SDG) Agenda back on track; using science and technology for good; and ensuring that multilateralism delivers for all countries".

The theme of the G77 summit from September 15 and 16 is Science, Technology and Innovation.

Before going to Delhi, he will attend the Africa Climate Summit in Nairobi on Monday and Tuesday and the UN-ASEAN Summit that will be held during the group’s summit in Indonesia from Tuesday to Thursday.

Reflecting on the four top-level meetings that lead up to the UN’s high-level meetings in New York, Guterres said: "This multiplicity of summits reflects the growing multipolarity of our world. Power is more diffuse. Different countries exert influence in different spheres".

While recognising that together, "these summits demonstrate the vitality of our multipolar international community", he warned that "multipolarity in itself does not guarantee peace and stability" and could lead to fragmentation.

"Without strong multilateral institutions, multipolarity could be a factor for escalating geostrategic tensions, with tragic consequences," he said. He said that "fragmentation is all but inevitable" unless multilateral frameworks are reformed.

"And with fragmentation, confrontation can come. Multilateral institutions will only survive if they are truly universal."

On September 18 and 19, world leaders will gather for a summit in New York on the UN’s SDGs, which will segue into the annual high-level meeting of the General Assembly.

At the meeting with the ASEAN, Guterres said that he will also take up the issue of Myanmar, where a military junta ousted the elected government in February 2021. He said that he will seek to "engage all sides of the conflict in Myanmar in dialogue, while stressing that the de facto authorities must release all detained leaders and political prisoners, and launch an inclusive process to return to the democratic institutions".

The ousted President Win Myint and State Counsellor Aung San Suu Kyi, who was the de facto government leader are in detention along with several members of parliament and other leaders. Myanmar is a member of the ASEAN, but its military leaders have been barred from participating in its meetings.