Draghi said Italy, which holds the rotating G20 presidency and which is co-hosting the forthcoming COP26 climate summit with Britain, would be "pushing countries to honour their climate pledges and, in some cases, stand ready to make bolder ones".

Heads of the G20 nations will convene in Rome on October 30, just a day before COP26 -- billed as vital to the success of the Paris climate deal -- gets underway in Glasgow.

The 2015 Paris Agreement committed nations to limit global warming to "well below" 2C and to strive for a safer temperature cap of 1.5C.

"The G20 includes countries that make up more than 80 percent of world GDP and over 75 percent of emissions," Draghi told a gathering of youth climate activists in Milan.

"We want to achieve a G20 commitment about the need to keep 1.5C within reach. And we want to develop long-term strategies that are consistent with 1.5C."

Several G20 members, including the European Union, have committed to carbon neutral economies by around mid-century.

But the UN says that global emissions must fall more than seven percent each year this decade to keep 1.5C in play.

Six years on from the Paris accord, the latest round of national emissions cutting pledges put Earth on course to heat a "catastrophic" 2.7C this century, according to a UN assessment this month.

The Intergovernmental Panel on Climate Change in August said that the 1.5C threshold would be breached by mid-century under all emissions scenarios, but that rapid decarbonisation could drag temperatures back below the cap by 2100.