Prime Minister Rishi Sunak on Friday promised Britain would build on the achievements of its presidency of the COP26 climate change summit in Glasgow, as Egypt prepared to host the next meeting to tackle global warming.
The UK hosted world leaders in Scotland last year, with nearly 200 countries coming together on a global deal to combat climate change and work towards net-zero emissions.
Sunak said at a reception at Buckingham Palace that he believed "the agreements we reached in Glasgow are a source of hope for the world" and insisted London's "global leadership will continue".
"It is the hope of many that the legacy of this summit, written in history books yet to be printed, will describe you as the leaders who did not pass up the opportunity, and that you answered the call of those future generations," Sunak told guests.
King Charles III invited more than 200 world leaders, business figures and environmentalists to the palace reception. Those attending included British fashion designer Stella McCartney and US climate envoy John Kerry.
Sunak spoke after changing his mind and deciding to attend the COP27 summit, having faced a storm of criticism for saying he could not go due to his busy schedule at home.
The summit starts in the Red Sea resort of Sharm el-Sheikh on Sunday.
Charles on the other hand has followed government advice not to go.
Sunak praised the monarch's devotion to environmental causes, saying Charles "has been working to help find practical solutions to climate change and biodiversity loss for more than 50 years".