China will not build new coal-fire projects abroad, a move that could be pivotal in tackling global emissions.

President Xi Jinping made the announcement in his address at the United Nations General Assembly.

China has been funding coal projects in countries like Indonesia and Vietnam under a massive infrastructure project known as the Belt and Road initiative.

But it has been under pressure to end the financing, as the world tries to meet Paris climate agreement targets.

"China will step up support for other developing countries in developing green and low-carbon energy, and will not build new coal-fired power projects abroad," Mr Xi said in a video recording at the annual summit.

No further details were provided, but the move could limit the expansion of coal plants in many developing countries under China's Belt and Road Initiative (BRI).

The BRI has seen China fund trains, roads, ports and coal plants in numerous countries, many of them developing nations. For the first time in several years however, it did not fund any coal projects in the first half of 2021.

China is also the world's largest greenhouse gas emitter and is heavily reliant on coal for domestic energy needs.

Mr Xi mentioned promises made last year about China achieving peak emissions before 2030 and then transitioning to carbon neutrality by 2060.