China on Tuesday defended its energy policy a day after three influential green organisations criticised its dependence on coal.

"The Chinese government attaches great importance to the development and exploration of clean energy," foreign ministry spokeswoman Jiang Yu told reporters.

"It has been making great efforts to increase the share of clean energy in the energy mix."

A report commissioned by Greenpeace, the Energy Foundation and WWF on Monday said China's dependency on coal was creating hidden environmental and other costs worth more than seven percent of its annual gross domestic product.

The unaccounted costs equated to an estimated 1.7 trillion yuan (250 billion dollars), and would be even higher if the impacts in terms of climate change were included, according to the report.

China depends on coal for about 70 percent of its booming energy needs, which is one factor in its huge increase in greenhouse gas output in recent years.

Jiang said China had implemented a range of policies to tackle the problem.

"We have reissued a renewable energy law and encouraged development of all sorts of renewable energies, including green energy, solar energy, water and hydro energy, thermal energy," she said.

"We also attach importance to the clean use of coal, and we have done a lot to control the emission of pollutants produced in burning coal."

Still, China ranks alongside the United States as one of the world's two biggest emitters of the gases that are blamed for climate change.

Jiang said China would continue to step up efforts to develop renewable energy.