"It is not everything we or others wanted but is a step forward for us all," Miliband said in a statement released shortly after the deal was announced.

He added the pledge to provide $300 billion a year in finance by 2035 to the developing world "rightly reflects the importance of going beyond traditional donors like Britain, and the role of countries like China in helping those on the frontline of this crisis".

"If this finance is used in the right way, it could cut the equivalent emissions of one billion cars and could protect nearly a billion people from the impacts of climate change," he said.

Miliband -- a former leader of Britain's ruling Labour party, which returned to power in July -- argued the overall deal "sends the signal that the clean energy transition is unstoppable".

He insisted it "will drive forward the clean energy transition which is essential for jobs and growth in Britain and for protecting us all against the worsening climate crisis".

"It is the biggest economic opportunity of the 21st century and through our championing of it we can help crowd in private investment," the UK's energy secretary added.

Miliband conceded there was "much more work to do" if the world was to "prevent climate catastrophe" but that the UK had "pushed for ambition in Baku".

"We will keep up the pace, working with other countries before the world meets again in Brazil for COP30," he said.

"Only by doing this can we keep future generations safe and reap the benefits of the clean energy revolution."