Athens  - A deal at the climate change conference in Copenhagen next month is critically needed in order to curb migration UN Secretary-General Ban Ki-moon said Wednesday.

"We are in a critical period... populations will relocate due to more extreme weather including prolonged droughts, intensive storms and wildfires," Ban said at the 3rd Global Forum on Migration and Development, citing the rising migration numbers in Africa due to desertification and in Asia because of flooding.

Ban said the threat is already evident in poor countries, such as Bangladesh where floods have temporarily displaced millions and in Africa where expanding desertification is prompting more people to leave rural areas.

"We need action and agreement in Copenhagen. We will continue to push for the most ambitious agreement possible," he said.

World governments are scheduled to meet in the Danish capital December 7-18 to agree on a new protocol before the Kyoto Protocol expires in 2012.

The EU's 27 member countries last week reached a compromise on how much money to offer developing countries to fight climate change, a key stumbling block for a global treaty.

Estimates by the European Commission, the EU's executive, predict that rich nations will have to offer developing countries around 100 billion euros (147 billion dollars) per year by 2020 to tackle climate change.

During talks at the UN conference in Athens, Ban said the number of people living outside their country of birth was more than ever before, due to poverty and war.

"Today the number of international migrants is greater than at any other time in history, with 214 million people living outside their country of birth," he said.

He said the recent global recession has highlighted the vulnerability of migrants, as many often lack safety nets and cannot afford to return home while special attention should be also paid to the most vulnerable migrants of all - victims of human trafficking.(dpa)