NEW YORK -- Four countries on four continents launched a joint initiative June 23 aimed at giving the United Nations new impetus to revitalize the spirit of the 1992 Earth Summit in Rio de Janeiro and achieve sustainable development while tackling environmental problems.

During the special session of the U.N. General Assembly, being held here to review the implementation of environmental measures adopted at the Rio summit, German Chancellor Helmut Kohl took the initiative in bringing Brazil, South Africa and Singapore together to work on such issues as forests, urbanization, transportation and climate change.

"We represent four countries on four continents. We are a microcosm of the world. The fact that we are able to forge a partnership to launch this joint initiative augurs well for the future," their joint statement says.

More than 100 reporters and television crews packed a hotel room near the United Nations for the news conference in which Kohl announced the initiative together with the president of Brazil, the deputy president of South Africa and the prime minister of Singapore. The initiative is to "demonstrate that it is possible for North and South to take joint action on this vital issue for mankind," Kohl told reporters. "It is unusual to take this form. We are different, but it is important to act in common to tackle environmental problems."

Singapore Prime Minister Goh Chok Tong said the group will focus on small-scale projects, adding that his country can contribute to solving pressing urban problems. In the statement, the four countries for a move away from fossil fuels and toward developing renewable forms of power, including solar energy.

They also called for a conference in Berlin in 2000 to bring together leaders from the world's 21 largest cities, and urged the creation of U.N. guidelines for public transportation systems.