President Biden will not attend a major United Nations climate summit that begins Thursday in Dubai, skipping an event expected to be attended by King Charles III, Pope Francis and leaders from nearly 200 countries, a White House official said Sunday.

The official, who asked to remain anonymous to discuss the president’s schedule, did not give a reason Mr. Biden will not make an appearance at the two-week summit, known as COP28.

But senior White House aides suggested that the war between Israel and Hamas had consumed the president in recent weeks and days, as he pressed for a pause in fighting and release of hostages held by Hamas.

“They’ve got the war in the Middle East and a war in Ukraine, a bunch of things going on,” John Kerry, Mr. Biden’s special envoy for climate change, said last week. Mr. Kerry and his team will be in Dubai.

Kirsten Allen, a spokeswoman for Vice President Kamala Harris, said last week that Ms. Harris had no plans to attend COP28.

Addressing global warming has been a central domestic and international issue for Mr. Biden, who earlier this month called climate change “the ultimate threat to humanity.”

For the past two years, Mr. Biden has attended the annual U.N. climate conference, the location of which changes. In 2021, Mr. Biden traveled to Glasgow for the talks, where he apologized for the United States briefly pulling out of a global climate pact under President Donald J. Trump, who mocked climate science.

Last year, he made a three-hour stopover in Egypt for the summit, where he reasserted American leadership in the global fight against climate change, and promoted the passage of the country’s most significant climate law. That legislation, the Inflation Reduction Act, is pouring at least $370 billion into clean energy over the next 10 years. Mr. Biden told the assembled leaders that it would help the rest of the world pivot away from fossil fuels.

Climate activists are likely to be angered by Mr. Biden’s decision to forgo this year’s U.N. talks. But analysts said it was not typical for a U.S. president to attend every climate summit.

In Dubai, leaders are expected to discuss their progress, or lack thereof, in limiting global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) over preindustrial levels.

That’s the threshold beyond which scientists say that humans will have trouble adapting to intensifying wildfires, heat waves, drought and storms. In 2015, countries agreed to cut emissions from burning coal, oil and gas to keep global warming “well below 2 degrees Celsius” and ideally no more than 1.5 degrees Celsius.

But the planet has already warmed an average of 1.2 degrees Celsius, and while the United States and some other countries have reduced their greenhouse gases, global emissions are continuing to rise.

Scientists say that the world must reduce emissions 43 percent below 2019 levels by 2030 to avoid catastrophic impacts from climate change. But current national climate plans will achieve only a 7 percent reduction.

In Dubai, nations are expected to discuss ways to increase climate action and debate whether to agree to a phaseout of fossil fuels.

David Victor, a nonresident senior fellow at the Brookings Institution, a Washington think tank, said the work could be handled by Mr. Kerry and others.

“I don’t quite see why you send a president to an event that doesn’t have a marquee outcome,” Mr. Victor said. Mr. Biden’s absence, he said, sends “a message that there’s not much to be done by sending a leader.”

About 70,000 people are expected to attend COP28. The United States is likely to come under fire at the summit for not following through on pledges to help developing countries transition to clean energy and adapt to climate change.

Alden Meyer, a senior associate at E3G, an environmental research organization, said he thought it was important for the leaders including Mr. Biden and President Xi Jinping of China to attend the summits. But he noted that the United States and China, the world’s two largest emitters, recently established a joint agreement to boost renewables with the goal of displacing coal, gas and oil.

“If President Xi and President Biden can build on that work that their two special envoys did, that could be more important than them actually showing up and participating with dozens or hundreds of other world leaders in scripted dialogues,” Mr. Meyer said.