Rising sulphur dioxide emissions in China are causing environmental harm and economic loss, the government says.
Pollution problems have grown along with China's economy
China is the world's largest sulphur dioxide polluter, emitting nearly 26m tons of the gas in 2005.
This was a 27% increase since 2000 and coincided with a rise in coal consumption, the State Environmental Protection Administration (SEPA) said.
The gas contributes to acid rain, which damages buildings, soil and crops, and can cause health problems in humans.
Li Xinmin of SEPA's air pollution department told a press conference that much of the pollution came from burning coal.
"Coal accounts for 70% of China's energy consumption. This fact is hard to change in a short term," he said.
China was working to cut sulphur dioxide emissions from power plants, he said, and the government had set a 10% reduction goal to be achieved by 2010.
Mr Li also pledged more effort to improve the air quality in Beijing ahead of the Olympics in 2008.
He said "remarkable results" had been achieved by phasing out things like coal-burning boilers, old vehicles and diesel-powered buses.
Mr Li's comments come amid mounting concern over the environmental impact of China's rapidly expanding economy.
China's booming economy is demanding more energy
In July, China announced it planned to spend 1.4 trillion yuan ($175bn) over the next five years on protecting its environment.
The sum - equivalent to 1.5% of China's annual economic output - will be used to improve water quality, and cut air and land pollution and soil erosion.
But Mr Li hit back at reports the pollution was affecting other nations.
Last week, the Associated Press news agency reported that researchers on the west coast of the US were monitoring the impact of pollution from China.
The report said that the US Environmental Protection Agency estimated that on certain days nearly 25% of pollution in the skies above Los Angeles could be traced to China.
Mr Li dismissed the claims and said further study was required.
"Those reports saying 25% of pollution in Los Angles comes from China are not objective and are irresponsible and the conclusion is also doubtful," he said.