In addition to curbing the pollution of the city's 3.3 million vehicles, Beijing has taken other measures. These include relocating the city's major steel makers and prohibiting neighboring provinces from burning straw.

"We have the confidence and capacity to provide good air quality for the Beijing Olympics," Du said.

His confidence does not seem out of nowhere.

Statistics showed air quality in Beijing had improved for nine straight years since its Olympic bid in 1998. Major air pollutants, including sulfur dioxide, carbon monoxide and carbon dioxide, have decreased by 10 to 60 percent.

"China has made achievements in the past five years what it took the Europe 20 to 25 years to achieve in terms of the air quality improvement," said Ivo Allegrini, head of the Institute for Atmospheric Pollution of the Research National Council in Italy.

The Beijing Olympic Games take place on August 8-24, followed by the Paralympics September 6-17. About 500,000 foreigners are expected to attend.

A couple of days ago, China's Vice President Xi Jinping ordered strengthening efforts in improving the environment and air quality and living up to the promise of sound air quality during the Olympics.

The government has officially included foreigners in a 12 member expert panel on air quality during the Games. Such a make up would ensure the authority and transparency in air quality monitoring and forecasting during the Games.