RIO DE JANEIRO - A total of 692 voluntary agreements were made in the main and side events of the United Nations Conference on Sustainable Development (Rio+20), Rio+20 Secretary-General Sha Zukang said Friday.

"Rio+20 is about implementation and concrete action. Here we saw that governments, UN system and major groups are committed in a serious manner. Voluntary agreements are a fundamental part of the conference's legacy and complement to the Rio+20 official document," Sha said at a press conference on the last day of the high-level summit.

He said governments cannot pursue sustainable development on their own, and they need support of private sectors and the civil society.

Voluntary agreements were closed by governments, NGOs, and major groups, which include 500 companies and universities.

Governments were involved in 50 of the 692 commitments, accounting for only 7 percent of the total.

Agreements involving NGOs and the UN system reached 72, and 226 agreements involved companies and industries, and 243 involved schools and universities all over the world.

The Asian Development Bank and eight of the world's main multilateral development banks are committed to investing $175 billion in sustainable transport systems.

Fifty billion dollars will be invested in UN Secretary-General Ban Ki-moon's Sustainable Energy for All initiative. The total amount to be invested reaches 513 billion dollars and will benefit several sectors including transportation, energy, carbon emission reduction, deserts, and climate change.