Climate cooperation between China and the Republic of Korea carries special significance, especially in light of the United States' withdrawal from the landmark 2015 Paris Agreement, former United Nations secretary-general Ban Ki-moon said.

Addressing the China-ROK Roundtable on Climate Change Cooperation, which was held on the sidelines of the Boao Forum for Asia on Friday, he highlighted the critical role of China and the ROK as major economic engines in Northeast Asia and key actors in the global transition toward sustainable development.

"The policies and partnerships that emerged from our collaboration can have a powerful impact, not only for the region, but for the whole world, which is undergoing tumultuous times," he said.

He stressed climate change as a defining challenge that no nation can address alone.

"The atmosphere does not recognize national borders ... Our solutions, therefore, must also transcend borders," Ban Ki-moon emphasized. "We can negotiate many difficult and thorny issues between and among countries, but we cannot negotiate with our nature."

Recalling the role that China and the US played in consolidating unity and laying the foundation for the Paris Agreement, he expressed strong disappointment at seeing the US withdraw from the treaty for the second time under the Donald Trump administration.

"This is a very historic issue and a very, very important issue which we must not forget ... I'm sure that the US will return after his term is over. But by that time, climate change would have moved their own course," he noted.

The present situation has underscored the importance of the climate dialogue between China and the ROK, he said.

"China and Korea have already shown promising leadership in this regard through investment in renewable energy, green technologies and climate innovation, and continued collaboration in areas such as carbon markets," he said.

A dialogue such as this helps build understanding, share best practices and inspire new partnerships, he said. It also sends a powerful signal that regional cooperation can play a constructive role in addressing global challenges.

"The window for meaningful climate action is narrowing rapidly. The choices we make today will determine the future we leave to our children and grandchildren and succeeding generations," he said.

Liu Zhenmin, China's special envoy for climate change, said Asia accounts for about 57 percent of global electricity consumption, a testament to the region's robust economic dynamism.

China and the ROK, as economic front-runners in Asia and key players in global climate governance, already boast world-leading advantages in renewables, batteries and nuclear energy, he continued.

Amid global growth, heightened geopolitical tensions, and the resurgence of unilateralism and protectionism, the envoy called on the two countries to stand firm in upholding multilateralism, reject destabilizing interference, and strengthen solidarity and cooperation.

Li Zheng, director of the Institute of Climate Change and Sustainable Development at Tsinghua University, highlighted the complementary strengths between the two nations.

China holds practical advantages in large-scale wind and solar development and the construction of new power systems, while the ROK excels in nuclear power, high-end manufacturing and international standardization, he said.

Li proposed that the two countries establish joint research platforms in energy storage, hydrogen, CCUS (carbon capture, utilization and storage), and smart grids, leveraging the latest advances in artificial intelligence.

He also called for third-party market cooperation to integrate China's green manufacturing and engineering construction capabilities with the ROK's advantages in technical standards.

"Climate cooperation between China and South Korea is underpinned by shared goals and significant complementary strengths, offering vast space and enormous potential for collaboration," Li said.