RIO DE JANEIRO- Developing countries like Brazil and China have played an important role in helping achieve consensus on sustainable development at a just wrapped-up UN conference, a Brazilian delegate said here Friday.

"Thanks to partners like China, we managed to reach an ambitious document, which preserved the main concerns of developing countries," Andre Correa do Lago, Brazil's chief negotiator to the conference, told Xinhua.

He referred to an agreed final document issued at the end of the UN Conference on Sustainable Development (Rio+20).

Consensus was achieved through intense consultations, he said, adding discussions on climate change in the BASIC bloc -- Brazil, South Africa, India and China -- became more frequent ahead of the Rio+20 conference.

The final document reaffirmed the Rio Principles introduced 20 years ago, which stated that countries shared "common but differentiated responsibilities" in sustainable development.

Lago said it was extremely positive and reflected the changes which affected the world in the past two decades.

"Rio92 (the Rio conference held in 1992) happened when major advanced countries believed they had defined what the best way to develop was. This conference takes place in a moment when developed countries are undergoing a great crisis, and developing countries like Brazil and China became much more important," Lago said.

It was "very positive" for countries to realize that there was no fixed development model, he added.

The diplomat admitted there are differences between the two major emerging economies, such as population or carbon emissions sources, but the agreement on solving environment issues with economic social approach, knit the two countries together, he said.

Brazil and China are not developed countries, but they are committed to contributing to the containment of climate change, he said.

"Both countries advanced a lot in the past years, but they still have a lot of ground to cover," Lago noted, adding China's capacity to develop technology and seek innovation in large scale enables the Asian country to overcome the biggest challenges of sustainable development: rooting out poverty and raising production and consumption standards.

Green economy, another hot topic at the conference, cannot replace sustainable development, though it was a good notion, Lago said.

Developing countries must find solutions that are sustainable in social, economic and environment aspects, instead of ways that only address economic needs, he added.