MILAN - Italy wants the G20 summit in October to make a commitment about the need to limit human-caused global warming to 1.5 degrees Celsius and develop long-term strategies consistent with that goal, Prime Minister Mario Draghi said on Thursday.

Speaking at the Youth4Climate meeting in Milan, Draghi said he was pushing countries to honour their climate pledges and stand ready, in some cases, to make bolder ones.

"The ecological transition is not a choice - it is a necessity," he told the conference of thousands of youth activists who converged on Milan this week.

He added wealthy nations who pledged a decade ago to mobilize $100 billion a year to help vulnerable countries adapt and transition to cleaner energy needed to fulfill that pledge.

(Reporting by Stephen Jewkes, writing by Agnieszka Flak) ((agnieszka.flak@thomsonreuters.com; +39 06 8030 7754;))