SHARM EL SHEIKH, Egypt (AA) – World leaders gathered in Egypt’s Red Sea resort city of Sharm el-Sheikh on Monday for UN climate summit COP27 to discuss ways of tackling climate change.

Addressing the summit, which officially began on Sunday, Egyptian President Abdel Fattah El-Sisi called on world leaders to act with urgency to implement their commitments.

“There is no time to slip back. There is no space for hesitation,” al-Sisi said in his opening remarks. “For the sake of future generations, here and now we are facing a unique historical moment, a last chance to meet our responsibilities.”

UN Secretary-General Antonio Guterres, for his part, warned that the world was on the “highway to climate hell”.

“Climate change is on a different timeline, and a different scale,” he told the summit. “It is the defining issue of our age… It is unacceptable, outrageous and self-defeating to put it on the back burner,” he said.

The UN chief warned that the world was fast approaching tipping points that will make climate chaos “irreversible.”

“Humanity has a choice: cooperate or perish,” he said. “It is either a Climate Solidarity Pact, or a Collective Suicide Pact.”

UAE President Sheikh Mohamed bin Zayed Al Nahyan said climate change affects stability and security in the world.

He issued an “open invitation to find practical solutions to address losses and creating sustainable economic growth for all humanity.”

“The future of future generations depends on the steps we take today,” he stressed.

Earlier Monday, al-Sisi and Guterres welcomed several leaders to participate in the global event, including bin Zayed, French President Emmanuel Macron, Algerian President Abdelmajid Tebboune, Bulgarian President Rumen Radev and British Prime Minister Rishi Sunak.

Taking place from Nov. 6 to 18, the summit began on Sunday with a speech by COP26 president Alok Sharma to mark the formal handover to Egypt.

According to Simon Stiell, chief of the UN Framework Convention on the Climate Change, 110 leaders and heads of states are expected to participate in COP27, in addition to thousands of representatives of civil societies.*Ikram Imane Kouachi contributed to this report.