WASHINGTON: World leaders have reached a new agreement on tackling climate change.

Delegates agreed that developing countries will have to face targets for cutting greenhouse gas emissions as well as rich countries.

The informal meeting in Washington of the G8+5 Climate Change Dialogue also agreed that a global market should be formed to cap and trade carbon dioxide emissions.

The group is a discussion forum that is part of British-led environmental mission, including politicians and business leaders from the world's major industrialised nations.

The announcement will be seen as a major coup for the British Government because the discussion forum was launched at the House of Commons in February 2006 and its president, Elliot Morley MP, is a special representative of Tony Blair.

The forum's closing statement yesterday said man-made climate change was now "beyond doubt".

A statement added: "Climate change is a global issue and there is an obligation on us all to take action, in line with our capabilities and historic responsibilities."

The declaration carries no formal weight but it is considered to indicate a real change in mood by the most powerful nations.

The two-day meeting brought together legislators from countries including the Group of Eight rich nations plus Brazil, China, India, Mexico and South Africa.

Former cabinet minister Stephen Byers took part in the forum, joined by influential US senator Joe Lieberman and presidential candidate John McCain.

British businessman Sir Richard Branson, German Chancellor Angela Merkel, and Paul Wolfowitz, President of the World Bank, all gave keynote addresses.