"China will increase support for other developing countries to develop green and low-carbon energy and will not build new coal-fired power projects abroad," Xi Jinping said in a pre-recorded speech to the assembly.
China has developed a lot of infrastructure projects around the world and has been open to coal power projects abroad until now, reports AFP.
However, China will continue to extract energy from coal at home, promising to be free of coal power only by 2060.
The new commitments from China to take more responsibility for reducing carbon dioxide emissions and combating the climate crisis come before the UN conference in Glasgow in November. Then the hope is to raise the ambitions for the Paris Agreement.