China must step up and help lead the fight against climate change, starting with a strong new climate target, the United Nations’ top climate official said Friday.

Simon Stiell, executive secretary of U.N. Climate Change, touted China’s investments in clean energy technology as a demonstration of “leading by example.” He then implored the world’s largest emitter to release a strong new plan to cut its planet-warming pollution — known as a nationally determined contribution, or NDC. 

“A strong NDC would send an important signal to other countries that stronger targets drive investment, that courageous leadership pays off, that development and sustainability are not at odds — that they are compatible,” said Stiell, speaking on the sidelines of the global climate talks in Baku.

His comments, delivered at an event on China’s support for developing nations, come as global climate talks proceed in the shadow of a government transition in the United States, the world’s largest economy and second-biggest emitter. 

The U.S. has traditionally taken a key leadership role at these global summits, pushing countries like China to do more to cut their emissions faster. 

But President-elect Donald Trump has disputed the science behind global warming and promised to withdraw the U.S. from the Paris Agreement, the landmark deal that calls on countries to collectively tackle climate change. Trump exited the deal in his first term, but President Joe Biden rejoined in 2021.

Stiell noted that this year’s global climate summit and the next, known as COP29 and COP30, will be “critical” for global efforts to limit rising temperatures. 

“We will need China’s continued leadership,” Stiell said.

Countries at this year’s COP29 summit will need to agree on a new sum for global aid to help developing countries address climate change. Traditional rich country donors, such as the U.S. and European nations, are calling for China and other high-emitting, emerging economies to start chipping in.

China has pushed back — arguing that it already contributes significant funding to help developing countries through training, joint research and direct financial support. China has provided nearly $25 billion (177 billion yuan) for climate efforts in the Global South since 2016, according to its officials.

Jennifer Morgan, Germany’s climate envoy, on Thursday commended China’s efforts but said: “The question remains as to exactly what money flows are being counted here. The quality of the financing is also still unclear at present … It shows that China has already done a lot and is already doing a lot. But only what is reported transparently will be recognized.”

As part of the COP29 negotiations, countries will also be discussing the transparency of their support and the need for it to come in the form of below-market-rate loans or grants rather than high-interest-rate loans.

The money is considered necessary to ratchet up the emissions cuts countries are meant to pledge in their next round of climate targets due in February.

China is currently pledging to peak carbon dioxide emissions by 2030 and zero them out by 2060. U.S. officials, pointing to several analyses, say China needs to commit to slashing at least 30 percent of its emissions by 2035.

Zhao Yingmin, head of China’s COP29 delegation and deputy minister at China’s ecology ministry, told POLITICO that “the entire international community should work together to deal with the crisis we are facing.” 

Asked if Beijing would deliver a strong NDC and show the leadership Stiell demanded, he said: “China has contributed in addressing climate change. But in the future, China will do our best to contribute more.” 

Zhao would not say whether China would consider counting its South-South funding, the money Beijing invests in other developing countries, toward the new goal. The responsibility for the new finance goal “lies with developed countries, not developing countries,” he added. “But developing countries will also help other developing countries according to the South-South cooperation framework.”

U.S. diplomats representing the Biden administration in Baku say they’re still pushing to drive climate action forward at the event. Biden is preparing to submit a new NDC to signal what the U.S. could do — even if Trump is unlikely to deliver it.

They’ve also called on China — and other countries — to do more.

If the U.S. is no longer able to project climate leadership over the next four years, White House national climate adviser Ali Zaidi said earlier this week, “that will come to the detriment of U.S. businesses and U.S. workers, but also to the global dialogue, and we will be, as a collective, looking for other countries to step up to the plate.”