Johannesburg, South Africa ? The World Summit on Sustainable Development opened here Monday with the lofty aspiration that representatives of more than 190 nations will agree on a plan to develop the poorest countries without further fouling air, polluting water or degrading land. Yet negotiations quickly got bogged down with impoverished countries demanding more aid and wealthy nations reluctant to give it.

South African President Thabo Mbeki opened the meeting with a call for participants to pursue the goals adopted a decade ago at the Earth Summit in Rio de Janeiro, Brazil. Those included reversing “environmental destruction, poverty and inequality.” Unfortunately, little progress has been made, he told the delegates from around the globe.

Residents in the overcrowded Alexandra township of Johannesburg, South Africa, live in shacks, many without access to electricity, running water or basic sanitation. Just three miles away in the posh suburb of Sandton, delegates to the World Summit are discussing poverty.

“The tragic result of this is the avoidable increase in human misery and ecological degradation,” he said.

The 10-day, United Nations-sponsored conference has drawn about 12,600 people so far, including 5,730 government representatives.

The goals of the conference include reducing by half the number of people without access to clean water, 1 billion, and without proper sanitation, 2 billion. Other goals are to supply the poor with cheap but renewable energy and proper health care, and to reverse the despoiling of agricultural land.

A number of countries want an action plan to accompany the “Johannesburg Declaration” that would set unambiguous goals and also dates by which nations would have to show measurable progress.

Such commitments, although not legally binding, are also sought for expanding the world’s reliance on solar, wind and other renewable energy sources to reduce its use of fossil fuels and the resulting pollution and emissions of globe-warming gases.

The Bush administration, which pulled out of the international Kyoto Protocol, which was designed to reduce greenhouse gases, has so far resisted setting specific goals and timetables.

Developing nations want the United States and other wealthy countries to more than triple the amount of foreign aid they provide.