King Abdullah II of Jordan almost immediately turned his speech to the war in Gaza, calling attention to more than 13,000 Palestinian civilians killed by Israel’s military campaign, according to Gazan health authorities, and saying that leaders should not talk about climate change “in isolation from the humanitarian tragedies unfolding around us.”

“As we speak, the Palestinian people are facing an immediate threat to their lives and well-being,” King Abdullah said. “In a region already on the front lines of climate change, the massive destruction of war makes the environmental threats of water scarcity and food insecurity even more severe.”

The more than two million Palestinians trapped in Gaza have spent much of the past two months searching desperately for food and water as the Israeli military laid siege to the territory, which is run by Hamas, the armed group that led the Oct. 7 attacks in Israel that killed around 1,200 people, according to the Israeli authorities.

As the war threatens to metastasize into a wider regional conflict, Jordan, which borders Israel and the West Bank, is one of the countries that is most vulnerable to spillover. Much of the country’s population is of Palestinian descent, and fury toward Israel and the United States has swept across the Middle East since the outbreak of the war.

Speaking at the climate summit, President Recep Tayyip Erdogan of Turkey condemned the Israeli military campaign as a “war crime.”

“While we are here expressing our views on the climate crisis, it is impossible not to touch upon the humanitarian crisis taking place in the Palestinian territories close to us,” he said.

The president of Iraq, Abdul Latif Rashid, also called for protections for civilians and said he supported Palestinians’ “right to self-determination.”

Their remarks stood out partly for their setting: The summit’s host, the United Arab Emirates, led a push for Arab countries to establish diplomatic relations with Israel in 2020 in an American-brokered deal called the Abraham Accords. The Emirati government has maintained those ties throughout the war, even as the Israeli military campaign sparked grief and anger among Emirati citizens.

On social media, Mr. Herzog shared photographs from the sidelines of the summit. He met with world leaders, including the Emirati president, Sheikh Mohammed bin Zayed, and shook hands with the Qatari ruler, Sheikh Tamim bin Hamad, whose country had mediated the cease-fire negotiations between Israel and Hamas.

It was unclear whether Mr. Herzog and Mr. Abbas would speak on Saturday as the summit continues.