"What is still lacking is many of the details, and South Africa will add what it can to those details," he said.

The European Union's green supremo, Environment Commissioner Margot Wallstrom, said last week the conference could fail over dithering unless preparatory talks were accelerated.

The World Summit on Sustainable Development (WSSD), a follow-up to the 1992 Rio Earth summit, aims to hammer out a concrete set of action plans to pull people out of poverty without inflicting permanent damage on the environment.

It will be held from August 26 to September 4, with around 60,000 delegates including 100 heads of state, attending.

The agenda is to be finalised at a fourth round of preparatory talks in Indonesia in late May and early June.

"I'm not over concerned (about the pace of the talks)," Moosa said. "We're in April. If we had full agreement now, we wouldn't need a conference."

The EU's Wallstrom said last week the summit needed to set "realistic but ambitious targets", but she was not sure that governments would agree on a detailed action plan.

Moosa said the summit would follow the path blazed by the United Nations Millennium Declaration, which calls for, among other things, a halving by 2015 of the proportion of people who suffer from hunger or have no access to clean water.

"We want to translate the Millennium document into a plan of action," he said. "We should aim to agree on a Johannesburg programme of action."

Priority areas will include improving water access and quality, energy, health, education and food security.

A "progress report" will also be drawn up on the decade since Rio. Moosa said that while a lot had been accomplished, there were areas where there had been no progress.

He said there had been too much emphasis on the environmental aspects of sustainable development and not enough on the economic and social sides of the equation, which Johannesburg hopes to rectify.

He also said the world's affluent nations had not spent as much on development aid as they had committed themselves to at Rio.