"Exporting low-end steel products that devour a lot of energy and contaminate the environment is by no means acceptable," said the report from the National Development and Reform Commission (NDRC).

    The steel industry accounts for 15 percent of the country's total energy consumption and discharges 14 percent of the total pollutants, according to the report.

    On May 21, the government imposed export tariffs of five to 10 percent on more than 80 steel products, including steel wire, sheet and plate, and raised export tariffs from 10 to 15 percent on primary commodities such as steel billets, ingots and pig iron from June 1.

    "It may take for a while before the measures take effect and current demand for steel remains high in the global market," said the report, indicating fast growth of steel export would continue.

    The NDRC called for close monitoring of the effects of the policies and reiterated the principle of developing the steel industry based on domestic demand.

    Analysts believe the policies would fail to reduce exports in the short run, but would probably start to take effect from July.

    Export figures for May would still be "striking", said Zhou Xizeng and Li Hongliang, of CITIC Securities, as steel firms aimed to boost exports in anticipation of stricter controls.

    As the world's largest exporter of steel products, China exported more 20 million tons in the first four months, and some consulting firms estimate this year's exports at around 30 million tons.