Climate change and Covid-19 are top of the agenda as leaders from the world’s major economies meet in Italy.
It is the first time the G20 leaders are meeting face-to-face since the start of the pandemic.
However, China’s Xi Jinping and Russia’s Vladimir Putin will not be in Rome for the summit, choosing to appear via video link instead.
The meeting comes amid increasingly dire warnings for the future if urgent action is not taken to cut emissions.
The group – made up of 19 countries and the European Union – is estimated to account for 80% of the world’s emissions.
Speaking ahead of the two-day summit, UK Prime Minister Boris Johnson suggested failing to act would result in “our civilization” going backward, consigning “future generations to a life that is far less agreeable than our own”.
However, he acknowledged that neither the G20 meeting nor the upcoming COP26 summit in Glasgow, which begins on Monday, would stop global warming, saying “the most we can hope to do is slow the increase”.
According to Reuters news agency, a draft communiqué outlines a promise from the G20 to work towards limiting the rise in temperatures to 1.5C (2.7F) – but no legally binding agreement will be made.
The draft also pledges to take “concrete measures” to stop the illegal logging, mining and wildlife trades.
Editing by Tola Oguneye