Theresa May has announced millions of pounds in funding to help communities hit by climate change.
The prime minister's announcement came as international leaders gather in Paris to mark the second anniversary of the climate change plan agreed in 2015.
May has pledged £140 million of new funding to help build resilience to extreme weather events arising from global warming, while £15 million would be given to the Caribbean island state Dominica to help it recover from the devastation of Hurricane Maria in September.
Some £87 million will also be allocated for poor communities fighting against illegal logging, she said.
Britain, which will host a global Zero Emission Vehicle Summit in the autumn of 2018, will join Canada in a drive to phase out the use of "unabated" coal burnt without use of carbon capture and storage technology.
"Tackling climate change and mitigating its effects for the world's poorest are among the most critical challenges that we face. That is why I am joining other world leaders in Paris today for the One Planet Summit and committing to stand firmly with those on the front line of extreme weather and rising sea levels," May said ahead of her trip to the French capital.
"And by redoubling our efforts to phase out coal, as well as build on our world-leading electric car production, we are showing we can cut emissions in a way that supports economic growth."
The summit, hosted by French President Emmanuel Macron, will be attended by the president of the World Bank and the United Nations secretary-general.