French President François Hollande called on Tuesday for the upcoming United Nations climate conference in France to deliver an ambitious deal to address the growing global warming crisis. As mayors of almost 60 cities worldwide met at the Vatican climate conference with Pope Francis to sign a pledge supporting an international accord to confront global warming, Hollande delivered his address at the "Summit of Conscience for the Climate" in Paris before international dignitaries.

The UN climate conference, which is set to take place from Nov. 30 to Dec. 11 in Paris and create a new global agreement on addressing climate change by cutting greenhouse gases. The UN has previously set a goal of restricting global warming to 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial levels, according to Agence-France-Presse.

Hollande warned that the emission reduction targets of most countries were not enough to meet this goal of limiting climate change, reports the Associated Press.

"Today, with the agreement we see taking shape, we are still above 2 degrees Celsius, and probably three," Hollande said, according to AFP, adding that reaching a worthwhile deal would require "forsaking the use of 80 percent of fossil-based energy resources to which we still have easy access."

Hollande's comments came amid a growing push among world leaders to create a viable, ambitious and far-reaching accord to restrict carbon emissions globally. On Tuesday at the Vatican summit of mayors, Pope Francis said that he has "a lot of hope" that negotiators at the Paris climate talks will reach an agreement to reduce global warming, according to the New York Times.

Mayors at the Vatican summit are expected to sign a pledge supporting an international deal that says "human-induced climate change is a scientific reality and its effective control is a moral imperative of humanity, according to the Associated Press.

"The Paris summit is just months away," said New York City Mayor Bill De Blasio at the Vatican summit of mayors, reports The Hill. "We need to see it as the finish line of a sprint and take every local action we can in the coming months to maximize the chance that our national governments will act boldly."