China will never pursue temporary economic growth at the expense of environmental degradation, President Xi Jinping vowed on Friday.

"Those who made rash decisions regardless of the ecological environment, resulting in serious consequences, must be brought to account, and should be held accountable for a lifetime," he said.

"Only by implementing the strictest system and the most stringent rule of law can we provide reliable protection for ecological civilization."

Xi was speaking during a group study session attended by members of the Political Bureau of the Communist Party of China Central Committee and environmental scholars.

Meng Wei, head of the Chinese Research Academy of Environmental Sciences and an academician at the Chinese Academy of Engineering, was one of the two key lecturers at the session.

He told China Daily that by using the words "held accountable for a lifetime", Xi is referring to both requirements and inspirations.

"Officials are responsible for benefiting the people within their regions, not only in terms of gross domestic product, but also with green hills and clean water," Meng said. "Maintaining a good ecological environment should also be taken into account as part of officials' political achievements."

Xi reaffirmed the importance of balancing economic development and environmental protection, calling for an overall plan for land development, and for a scientific distribution of production, living and ecological space, leaving more room for nature to repair itself.

He emphasized the urgency of implementing major ecological restoration projects, and of enhancing ecological production capacity.

He said the idea of guarding the bottom line of national ecological safety should be firmly established.

Ecology: Xi says punishment for offenders must be tough

The bottom line regarding ecological and environmental protection issues should never be overstepped, otherwise offenders should be punished, he said.

Xi said environmental issues that threaten people's health should be particularly emphasized in environmental protection and pollution control, adding that a good environment is the fundamental basis for the sustainable development of society and humans.

"Prevention should always come first. ... Pollution prevention and control of water, air and soil should be stressed. Pollution control in key river basins, and airborne pollution treatment in key areas and industries should be promoted."

Meng said Xi has clearly set out the path that can lead China to becoming a beautiful country, as pledged by top leaders during the 18th National Congress of the Party in November.

"He highlighted the most important issues in promoting ecological civilization, explicitly asked that ideas on prevention and thrift should come first, and concluded that all requirements should be guarded by laws and systems."

China has been plagued by a series of pollution issues this year, including dense smog and haze covering more than 10 provinces and municipalities in January, and groundwater pollution in Shandong province, revealed first by posts on social media in February.

Recently, environmental issues have triggered public anxiety, with rice in Guangdong province found to be tainted with excessive levels of cadmium, a heavy metal believed to cause cancer.