China's overall air quality improved in 2014 and early 2015

The announcement came amid a spell of heavy smog in Beijing and the neighboring Tianjin municipality and Hebei province for the better part of a week.

The next step is to further optimize the country's industrial and energy structure and cut back on discharges of air pollutants, Chen said.p Authorities will go on slashing outdated capacity this year, shut down 1,000 small coal mines, improve the quality of coal on the market, ensure stable supply of natural gas, and promote the use of clean energy and energy-saving buildings.

They will aim to reduce discharges of SO2 and NOx by 3 and 5 percent respectively, and to "strictly control" that of VOC.

Chen said efforts will also be made to improve the evaluation of governments' implementation of air pollution control measures, deepen regional coordination, step up technological research and sharpen laws and regulations in the field, to make polluters pay the "unaffordable price".

China put into force a new Environmental Protection Law this year. A daily fine system was incorporated to punish offenders and motivate companies to expedite the costly modifications needed to reduce pollutants. In cases where fined violators fail to rectify the problem, the fine can increase without limit.

Chen said environmental authorities would "bring new tools introduced in the law into full play, conduct more covert inspections and seek heavier penalties for companies guilty of illicit or excess emissions and those which forge pollution data."

Government officials who neglect their duties or abuse their power will be investigated in line with law, he said.