SEOUL — The U.S. and China, the world’s two biggest carbon polluters, agreed to cooperate with other countries to curb climate change, just days before President Biden hosts a virtual summit of world leaders to discuss the issue.

The agreement was reached by John F. Kerry, the U.S. special envoy for climate, and his Chinese counterpart, Xie Zhenhua, during two days of talks last week in Shanghai, the State Department said in a statement.

“The United States and China are committed to cooperating with each other and with other countries to tackle the climate crisis, which must be addressed with the seriousness and urgency that it demands,” said the joint statement, issued late Saturday.

Meeting with reporters Sunday in Seoul, Kerry said the language in the statement is “strong,” and the two countries agreed on “critical elements on where we have to go.” However, the former secretary of State said, “I learned in diplomacy that you don’t put your back on the words, you put [it] on actions. We all need to see what happens.”

China is the world’s biggest carbon emitter, followed by the U.S. The two countries pump out nearly half the fossil-fuel fumes that are warming the planet’s atmosphere. Their cooperation is key to successful global efforts to curb climate change, but frayed ties over human rights, trade and China’s territorial claims to Taiwan and the South China Sea have threatened to undermine such efforts.

Noting that China is the world’s biggest coal user, Kerry said he had discussions with Chinese officials on how to accelerate a global energy transition. “I have never shied away from expressing our views, shared by many, many people, that it is imperative to reduce coal everywhere,” he said.

Su Wei, a member of the Chinese negotiation team, told state broadcaster CCTV on Sunday that a major accomplishment of the talks was “restarting the dialogue and cooperation between China and the United States on climate change issues.” Su said the countries reached a consensus on key areas for cooperation on climate issues.

Kerry is the highest-level U.S. official to travel to China since Biden took office in January.

Biden has invited 40 world leaders, including Chinese President Xi Jinping, to the virtual summit on Thursday and Friday.

The U.S. and other countries are expected to announce more ambitious national targets for cutting carbon emissions either ahead of or during the meeting, along with pledging financial help for climate efforts by less wealthy nations.

Le Yucheng, China’s vice minister of foreign affairs, signaled Friday, when Kerry was in Shanghai, that China is unlikely to make new pledges at the summit.

“For a big country with 1.4 billion people, these goals are not easily delivered,” Le said during an interview with the Associated Press in Beijing. “Some countries are asking China to achieve the goals earlier. I am afraid this is not very realistic.”

Asked whether Xi would join the summit, Le said that “the Chinese side is actively studying the matter.”

During a video meeting Friday with German and French leaders, Xi said climate change “should not become a geopolitical chip, a target for attacking other countries or an excuse for trade barriers,” though he called for closer cooperation on the issue, according to China’s official Xinhua News Agency.

Biden, who has said that fighting global warming is among his highest priorities, had the United States rejoin the Paris climate accord in the first hours of his presidency, undoing the withdrawal ordered by then-President Trump.

Major emitters of greenhouse gases are preparing for the next U.N. climate summit, set for November in Glasgow, Scotland. The summit aims to relaunch efforts to limit global temperature increases to 2.7 degrees Fahrenheit, as agreed in the Paris accord.

According to the U.S.-China statement, the two countries would be enhancing “their respective actions and cooperating in multilateral processes, including the United Nations Framework Convention on Climate Change and the Paris Agreement.”

The statement said both countries intend to develop long-term strategies before the Glasgow conference and take “appropriate actions to maximize international investment and finance in support of the transition from carbon-intensive fossil-fuel-based energy to green, low-carbon and renewable energy in developing countries.”

Xi announced last year that China would be carbon-neutral by 2060 and aims to reach a peak in its emissions by 2030.

In March, China’s Communist Party pledged to reduce carbon emissions per unit of economic output by 18% over the next five years, in line with its goal for the previous five-year period.

Kim writes for the Associated Press.