“The world is waiting for a solution that is long-term and economically viable,” U.N. Secretary-General Ban Ki Moon said in a video address to the 1,000 delegates from 190 nations gathered in Bangkok.

The week-long meeting stems from a breakthrough agreement in Bali last year to start negotiations to replace Kyoto, which only binds 37 rich nations to cut emissions of greenhouse gases by an average of five percent from 1990 levels by 2012.

U.N. climate experts want the new pact to impose curbs on all countries, although there is wide disagreement about how to share the burden between rich nations led by the United States and developing countries such as China and India.

No major decisions are likely from the Bangkok talks, which are intended mainly to establish a timetable for more rounds of talks culminating in a United Nations Climate Change conference in Copenhagen at the end of next year.

“We see this as very much a process-oriented meeting,” chief U.S. climate negotiator Harland Watson told reporters before the opening ceremony.

However, environmental groups are keeping a close eye on Bangkok for signs of sustained commitment by rich and poor countries alike to minimising global warming by curbing emissions of greenhouse gases such as carbon dioxide.

“It's the first test of whether the goodwill and good intentions that were present in Bali are still there when they get down to the hard negotiations,” said Angela Anderson of the Washington-based Pew Environment Group.