Chinese Premier Wen Jiabao has urged local governments to shut polluting plants and encourage families to save energy, marking his second appeal in just three days aimed at achieving energy efficiency.

Wen also said China would "proactively participate" in global talks on climate change, a statement published on the government Web site (www.gov.cn) said. He did not elaborate.

His appeal to local governments to further crack down on polluting factories in the second half of the year comes as China is rapidly overtaking the United States to become the world's top emitter of greenhouse gases.

Beijing is under rising international pressure to accept mandatory caps on carbon dioxide emissions from its factories and vehicles. China has refused to comply, but the government has shown greater efforts in addressing energy and environment issues.

Wen told a routine conference of the State Council, or the cabinet, on Wednesday that China would find it hard to achieve its energy consumption and pollution reduction targets, considering the current situation, the statement said.

"All levels of governments must clearly realise the difficulty and urgency of the energy-saving and pollution reduction task," Wen said in the statement, ordering them to give higher priority to environment and climate change-related work.

Local governments were instructed to "leverage all possible resources to enhance work and to seek substantial progress".

Detailing policy instructions for the second half of 2007, Wen said local governments must curb excessive growth in energy-intensive and polluting industries by measures such as keeping credit supply in check.

Inefficient facilities in thermal power, steel, alumina, iron alloy and cement sectors were ordered to be shut.

Wen said the government would focus on energy-saving projects and environment protection in polluted areas, and the government would also encourage energy saving by companies through price, tax, legal and administrative measures.

In addition, Wen hoped that "every company, every community, every organisation, every household and every citizen" would take part in programmes designed to reduce consumption of oil, gas and coal and to rein in emissions causing global warming.

Beijing has said that it aims to reduce emissions of major industrial pollutants by 10 percent and cut the amount of energy used to generate each dollar of national income by 20 percent between 2006 and 2010.

China was already behind target last year.