UN Secretary-General Antonio Guterres (Photo: AFP/ VNA)

Mr. Guterres said the climate crisis is worsening dramatically – but the collective response is lacking in ambition, credibility, and urgency.

G20 countries are responsible for 80 per cent of global emissions. The UN chief asked the G20 to commit to keeping the "1.5 degree goal alive" - referring to the 2015 Paris Agreement goal of limiting the global average temperature rise to well below 2°C above pre-industrial levels, and aiming for 1.5°.

The UN chief also called on G20 leaders to ensure a stimulus of at least 500 billion USD per year towards meeting the Sustainable Development Goals.

An effective debt workout mechanism is needed to support payment suspensions, longer lending terms and lower rates on fairer terms for poorer countries, he said.