"China has a good story to tell here in Rio and I hope it will tell it," Maurice Strong, former head of the UN Environment Program (UNEP), told Xinhua in an interview.

"I use China as an example of how a rapidly growing economy can still deal with environmental issues," said Strong Sunday, who was appointed the first executive director of UNEP when it was established in 1972 by the UN General Assembly.

China has been doing so even though it is difficult, because the "rapid growth in the economy tends to offset the progress China makes in environment," he said.

Strong recalled that he had worked closely with the Chinese delegation at the first UN meeting on environment held in Stockholm in 1972, which was chaired by him.

After the meeting, China dealt with all sorts of difficulties and established an environment protection agency in 1973, which was "very new at that time," he recalled.

Strong, who was also secretary-general of the last historic Rio Earth Summit in 1992, said China should share at the Rio+20 summit here its "good" story with other countries.

China should share "what it is doing and what it is planning to do with its harmonious development based on science," he said. "And China's policy is based on science."

For example, China is the only country he knew where officials are judged partly on their environmental performance, he said. "I don't know any other country doing that."

Strong also noted China still faces many challenges, like high energy consumption per unit of the GDP and air pollution, "but the progress is very good and the story which China has to tell is very good."

"China is setting an example, and it still has to move further domestically," he said. "But it is moving, its policies are moving in the right direction."

During the Rio+20 conference, China should share its experience, its progress achieved, and its policy for the future, he said. "The world cannot achieve sustainable development without China, and China cannot achieve its future without the world."

As a world leader, China needs the world and the world needs China, Strong said. "I am very convinced that China is the most important influence now in the modern world."

On June 20-22, more than 130 heads of state or government and tens of thousands of delegates will gather here to discuss a sustainable development blueprint and make important decisions on the global sustainable development process.

In comparison with its previous version 20 years ago, the Rio+20 summit comes at a time when it is very difficult to "get the kind of decisions that we need," Strong said.

"But hopefully, it can be the launching pad for a new period of positive negotiations and progress," he added.