He gave no further details of the meeting. Germany organised an international fresh water conference in Bonn last December, where delegates reiterated pledges to provide adequate supplies of drinking water worldwide.

Schroeder referred to last month's dramatic flooding in Germany, the Czech Republic, Austria and China. The floods, which killed dozens in Europe and hundreds in China, were blamed by some on global warming caused by burning fossil fuels.

"Climate change is no longer a sceptical prognosis, but a bitter reality. This challenge demands decisive action from us," Schroeder said.

He said the Earth Summit should pressure states to ratify the Kyoto Protocol on climate as quickly as possible so that it can come into force this year. He also appealed to nations such as the United States, Canada and Australia to make some contribution to climate improvement.

"For those industrialised countries that have not signed up, I appeal to them at least to contribute to an equivalent reduction of greenhouse gases," Schroeder said.