Chai Jing, former presenter and journalist with China Central Television, presents a self-funded documentary about smog in Beijing, Feb 28, 2015. [Photo/CFP]

Strict enforcement of law will be a focus in the environment protection efforts this year, and the cost on those involved in illegal production and emission will be too high to bear, Premier Li Keqiang said on Sunday.

During a press conference following the end of the annual parliament session, the premier said more support will be given to the environmental law enforcement departments, including assistance in capacity building.

"No one is allowed to use their power to meddle with the enforcement of the law," Li said when replying to a question if Sinopec and Petro China, as accused in a documentary, impose obstacles in the introduction of policies on environment protection and law enforcement in the sector. "The environment protection law is an ultimate weapon instead of a cotton swab."

In the documentary Under the Dome, former CCTV host Chai Jing accused the two oil giants of meddling with the setting of quality standard of gasoline consumed and wider use of natural gas.

"Chinese government is determined to tackle smog and environmental pollution as a whole and tremendous efforts have been made in this regard. But the progress still falls short of the expectation of our people," the premier said. "Last year in the work report I said we have declared a war against smog. We are determined to carry out our efforts until we achieve our goal."

He also said that the goal in the energy-saving and emission reduction sector has been placed high in this year’s government report.