British Prime Minister Gordon Brown's visit to China switches to environmental issues on Saturday, as he seeks to boost co-operation between the two countries on tackling climate change, senior Downing Street officials said.
Brown, whose focus on Friday was on furthering business links with the world's fastest-growing economy, is looking to secure backing for a new global deal on fighting greenhouse gas emissions for when the Kyoto Protocol expires in 2012.
How Britain can help China continue its rapid, but mainly coal-fuelled growth more sustainably will feature heavily as he leaves Beijing for the country's eastern financial hub of Shanghai.
"Climate change is a global challenge facing all regions of the world -- and one in which there can be no solution without engagement from all countries and collaboration between nations," officials travelling with Brown said in a statement.
"It is an urgent, complex issue that demands a comprehensive global and national response. China is as committed as Britain to achieving this.
"Only by acting now and working together to cut global greenhouse gas emissions can we leave the world a healthier and safer place for future generations.
"Neither the UK nor China has any choice but to meet this challenge."
On a post-Kyoto accord, the London officials said both countries need to intensify their efforts to secure a deal, although negotiations could be fraught because of tensions between developed and developing nations on binding targets.
Britain wants emissions cut targets for developed nations and greater technological and financial support for developing countries in return for stronger commitments from them to reduce greenhouse gases.
China -- on course to becoming the world's largest emitter of greenhouse gases -- opposes signing up to internationally agreed reductions and is instead pushing for more help from richer nations in creating "green" energy.
On Friday the two sides penned agreements to increase collaboration to reduce emissions growth and develop newer, cleaner technologies -- a sign they realise economic opportunities are arising from the global problem.
Brown also has a delegation of senior British business figures in tow.
One deal on climate change will see China get at least 50 million pounds (100 million dollars) from British government funds to back investment in energy efficiency, renewables, clean coal and carbon capture and storage.
Another on sustainable cities pledges Sino-British collaboration on building the low-carbon cities of the future. Brown will see at first hand efforts to construct the world's first sustainable city at Dongtan, near Shanghai.
The project is a joint venture between the bank HSBC and British design and engineering firm, Arup, which in part also designed Beijing's Olympic stadium for this year's summer games.
Brown has outlined plans to build five new "eco-towns" on disused industrial land to replenish Britain's depleted housing stock and encourage low- and eventually zero-carbon communities.
Elsewhere, Britain has committed itself to becoming the world's first country with legally binding targets for cutting carbon emissions, aiming for 60 percent, possibly even 80 percent reductions on 1990 levels by 2050.
But critics say London's position is contradictory as it backs the building of a new wave of nuclear power stations and expansion in the aviation sector.
China -- criticised for its heavy pollution -- has seen support for its aim of reducing the economy's energy intensity by 20 percent by 2010 and increasing use of renewable energy like wind and wave power by 15 percent by 2020.