"I strongly encourage the political authorities... of all nations not only to strengthen their actions to protect the environment," he said, but also to work towards the achievement of "binding international accords that are useful and fair for all."

Addressing new ambassadors to the Holy See, the pope said: "The problem cannot be addressed only at the individual level of each country."

Benedict urged "firmer and more widely shared commitments" to save the planet.

"The political and diplomatic deliberations at play in addressing the demands of such a complex matter test the resolve of stakeholders," the pope said earlier while accepting the credentials of new Danish envoy Hans Klingenberg.

He urged all parties to "forgo nationalistic or short-term alleged advantages in favour of longer-term benefits for the entire international human family."

World leaders voiced fears Thursday that the UN climate summit was heading for failure amid deep divisions over who must cut emissions and who pays for the devastation of global warming.

More than 120 leaders, including US President Barack Obama, are heading for the summit on Friday in a bid to rescue the 12 days of negotiations.

All rights reserved. copyright 2018 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.