Secretary-General Antonio Guterres said the UN has a "very solid commitment" for climate action, pointing out that African nations were the biggest victims of the globally changing weather patterns.
"We cannot be defeated by climate change and we are not yet winning this battle," he said yesterday at a ceremony in which Egypt took over the chairmanship of the 'Group of 77 (or G77) and China' from Ecuador.
"And it is clear to me that the biggest victims of climate change are members of the G77, namely African countries affected by drought or small island countries affected by the kind of hurricanes that we have seen or the rising levels of waters.
"But at the same time, of the largest economies of the world the two largest economies of the G77 are strongly committed to the leadership in climate action - and I refer to China and India," Mr Guterres was quoted as saying by a UN statement.
"In a moment when others are failing, I see the largest economies of the Group of 77 and China to be assuming the leadership in climate action to make sure that we don't suffer the dramatic and devastating impacts of climate change, as unfortunately we are already witnessing and things will get much worse if we are not able to defeat this threat," Mr Guterres said.
The G77 is the largest intergovernmental organisation of developing countries in the UN. Established on June 15, 1964, the group today has 134 members including India, the world's third largest emitter of greenhouse gases.
India had in 2016 joined the Paris agreement on tackling climate change.
UN chief Guterres had on May 31 last year warned world leaders that the impact of climate change could affect food production, water security and weather patterns "from Canada to India".
Stating that the "world is in a mess" he had urged the international community to "stay the course" even if one government does not believe in the emissions-cutting deal. Two days later, US President Donald Trump had announced America's withdrawal from the Paris Agreement.
Arguing that countries like China and India were benefiting the most from the Paris Agreement, President Trump had said that the agreement on climate change was unfair to the US as it badly hit its businesses and jobs.
The Paris Climate Agreement is a pact within the UN Framework Convention on Climate Change dealing with greenhouse gas emissions mitigation, adaptation and finance starting in the year 2020. According to the agreement, each country determines, plans and regularly reports its own contribution it should make in order to mitigate global warming.