Environment ministers from China, India, Brazil, Mexico and South Africa are taking part in the talks with their counterparts from the Group of Eight (G8) near Berlin.

"Without the cooperation of these countries, we will not be successful in this area," German Environment Minister Sigmar Gabriel said.

A spokesman for Gabriel's ministry said that no concrete decisions were expected from the Potsdam talks, which were designed to launch "an honest dialogue" on climate issues.

"International negotiations on climate control need urgent political momentum," he said. "This is the only way to master the challenge of the century."

Gabriel added that input from the three-day meeting would go into the G8 summit hosted by Germany in June and the UN climate conference on the Indonesian island of Bali in December.

Positions vary greatly

The German minister, however, did admit that finding a compromise would be difficult, as many developing countries regarded protecting the environment as a hurdle to their economic growth.

"The positions of the industrial states and developing nations are still far apart from each other," Gabriel said. "The interests of developing and emerging nations are the starting points for the debate."

Ministry sources said Germany, as leader of the G8, was looking for agreements between the bloc and emerging economies that would help to provide successor agreements to the Kyoto protocol.

2007 a 'decisive' year for planet

The 1997 treaty sets legally binding targets for developed countries to reduce emissions of carbon dioxide and other gases blamed for global warming by 2012 compared with 1990 levels.

"The year 2007 is a decisive one for international climate control," said Gabriel, adding that the Potsdam talks would seek to identify obstacles on the way to a post-Kyoto deal.

The minister said the talks between the emerging economies and G8 members Germany, France, Italy, Japan, Britain, Canada, the US and Russia would also discuss the best way to remove these obstacles.

"A meeting of this kind brings together the perpetrators of two-thirds of the world's greenhouse gas emissions and the consumers of around three-quarters of the planet's biological capacity," he said.

No climate protection without USA

In addition to climate issues, biodiversity will also be on the agenda of the meeting when the talks start in earnest on Friday morning after informal discussions over dinner on Thursday.

Head of the United Nations Environment Program, Achim Steiner, said on Thursday that no progress could be made to stop international climate change without the involvement of the United States. He also added that there was "no alternative to dialogue."

Gabriel, however, said he thought the US, the world's largest emitter of carbon dioxide, would join a coalition against global warming if developing countries also took part in a trading scheme to buy and sell the right to emit greenhouse gasses.

"The USA will not allow there to be an operating financial market that they are not a part of," he said. "I think at the end, the US will join."