The president of China and the president of the United States agreed on Monday to restart talks between their countries as part of international climate negotiations.

The talks between China and the United States over climate had been frozen for months due to tensions between the two countries. China retaliated for Speaker Nancy Pelosi's trip to Taiwan by suspending cooperation with the US.

The leaders of the world's two biggest economies, as well as the two biggest sources of fossil fuel emissions that are warming the planet, met for more than three hours on Monday before the Group of 20 summit in Indonesia.

In Sharm el Sheikh, delegates and activists at the UN climate conference were hoping for news that would spur more aggressive climate action from countries around the world.

The president of the Center for Climate and Energy Solutions said that the news was good for the climate talks.

In Egypt, thousands of diplomats and activists were focused on the meeting between Mr. Biden and Mr. Xi.

A lot is at stake, according to a Beijing-based policy adviser. He said that the United States and China needed to put aside their differences to send a message about the threat of climate change.

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The Chinese delegation and Mr. Biden had a bilateral meeting at the hotel before Mr. Biden opened his speech.

The world expects China and the United States to play key roles in addressing global challenges such as climate change and food security, according to Vice President Joe Biden. If you want, the United States is prepared to work with you.

The White House said after the meeting that the two leaders agreed to empower key senior officials to maintain communication.

John Kerry and Xie Zhenhua, Mr. Biden's climate envoys, have not had any formal negotiations in Sharm el Sheikh, where delegates are struggling with the question of whether industrialized countries should compensate developing nations for loss and damage from climate disasters.

ImageJohn Kerry and Xie Zhenhua are sitting in front of a blue backdrop with the World Economic Forum logo. Mr. Kerry is speaking and gesturing toward Mr. Xie, and they both have microphones in front of them.
The U.S. climate envoy John Kerry, left, and his Chinese counterpart, Xie Zhenhua, at the World Economic Forum in Davos, Switzerland, in May.Credit...Gian Ehrenzeller/EPA, via Shutterstock
John Kerry and Xie Zhenhua are sitting in front of a blue backdrop with the World Economic Forum logo. Mr. Kerry is speaking and gesturing toward Mr. Xie, and they both have microphones in front of them.

The two men have known each other for two decades and have met at least seven times. At one point, Mr. Xie clasped Mr. Kerry's arm.

At a crucial moment in the fight to limit global warming, the talks have renewed. Poor and rich nations are having a hard time coming to an agreement at the talks.

According to a climate policy expert at Chatham House in Britain, countries like to hide between the US and China because they don't want to be seen as doing enough to fight climate change. She said that the argument around ambition is removed when they come together.

As countries compete to dominate industries that will help the world pivot from fossil fuels, the discussions are happening.

The United States is poised to compete aggressively with China when it comes to the green economy following a landmark climate law signed by Mr. Biden this summer. At the climate talks in Egypt on Friday, Mr. Biden said the funding would clear the way for American innovation that would drive down the cost of renewable energy.

The United States and China have already warmed the planet by an average of 1.7 degrees Celsius, or 3.4 degrees Fahrenheit, compared with preindustrial levels. The likelihood of catastrophic climate impact will increase if the temperature rises by 1.5 degrees.

ImageA mock-up depicting clean power production, including wind turbines and solar panels, and distribution. It is in front of a red-walled entrance into the Chinese pavilion at COP27, featuring a “Welcome” sign.
A display at the Chinese pavilion of the United Nations climate conference in Egypt, where delegates hope news of the meeting between Mr. Xi and Mr. Biden will spur more aggressive climate action.Credit...Joseph Eid/Agence France-Presse — Getty Images
A mock-up depicting clean power production, including wind turbines and solar panels, and distribution. It is in front of a red-walled entrance into the Chinese pavilion at COP27, featuring a “Welcome” sign.

The first global warming pact in which both developed and developing nations pledged to cut greenhouse gases was made possible by previous deals between the United States and China.

Is it possible to meet 1.5 without the United States and China talking to each other? Mr. Li spoke. I can't see that

It's not clear how renewed cooperation between Washington and Beijing will translate into concrete agreements at the 27th Conference of the Parties to the United Nations Framework Convention on Climate Change.

There are disagreements between the two countries.

The United States wants China to commit to deeper emissions cuts in order to keep the global temperature from rising more than 1.5 degrees.

The issue of whether to create a fund to help poor countries cope with the loss and damage from continuing climate disasters, like the devastating floods in Pakistan and Nigeria, is the single largest issue facing negotiators in Egypt.

The creation of a new fund is being resisted by the Biden administration because they don't want to be held responsible for the high costs of disasters around the world.

Mr. Kerry said that China should contribute to any new pot of money that might be created because of its contribution to global warming. China, which is not an industrialized nation, is not happy about that.

Mr. Xie said that China isn't obligated to provide financial support under the UN climate rules. He said that Beijing is willing to spend money to help poorer countries.

The pressure is on both countries to mobilize more climate finance for poor countries. When Mr. Kerry and Mr. Xie sit down, she hopes that will be the focus.