Mayor Xu Zongheng stated Shenzhen's aim of becoming the pioneering city in China in terms of realizing sustainable growth, during an interview with six journalists from BBC World Service on Thursday.

"I'm deeply concerned with my city, and hope that your report will help more people around the world to better understand Shenzhen," the mayor said at the start of the interview, which lasted more than an hour. "I am open to questions and will try to tell you a true story of the city."

"Shenzhen has experienced the urbanization boom, also the quick growth in general trade and processing industries. Today the city is shifting focus to high-tech and high value-added sectors, especially biomedicine, medical equipment, semiconductor and environmentally friendly refined chemical industries," the mayor said.

He said that the new focus is the key to Shenzhen's future prosperity and sustainable growth, since the city, like many other Chinese cities, faces fierce market competition in traditional manufacturing sectors, stretched resources, and a heavy load on the environment.

"By 2030, Shenzhen hopes to become the pioneer in China in respect of sustainable growth. I am confident that our city has a brighter future," he said.

"The city government invested 11.5 billion yuan (US$1.43 billion) last year to protect the environment, accounting for 2.35 percent of the GDP. We hope to increase that proportion to 3 percent within five years. The money will be used to build 26 sewage plants, promote the use of natural gas instead of petrol, and impose the European III standard in exhaust emission control."

Asked why Shenzhen was especially attractive to skilled professionals, the mayor said apart from a mature market economy and a legal system that ensures fairness in competition, the city attracts people because it is a migrant city full of vitality, tolerant to digression from the norm.

"Besides, we are improving the medical system, expanding social insurance to cover migrants, building more schools for migrant children and bettering the living environment for residents."

Speaking of corruption, the mayor said Shenzhen has established laws and tighten supervision to fight it. "Every corrupt official will be punished," he pledged.

Xu, who is in his 50s, said he has a young mind and this helps him serve a young city like Shenzhen. "I love the city most in that it's full of vitality and creativity."

"The mayor impressed me as pragmatic and outspoken," said Chen Zhuang with BBC Chinese service.

Seven journalists from BBC World Service, invited by the provincial government, will conclude their eight-day tour of Guangdong on Tuesday.