China on Wednesday called on the US to honour its commitments to tackle climate change, after President Donald Trump moved to roll back American emissions targets set by his predecessor Barack Obama.

"The Paris Agreement was hard-earned. All parties of the international community, including China, had a common consensus on it," foreign ministry spokesman Lu Kang told reporters at a regular press briefing.

"All parties should conform to the historical trend of the time, seize the opportunity, honour their commitment, take practical and positive actions and implement the agreement."

The comments came after Trump declared the end of a "war on coal" Tuesday, signing an order to review Obama's "job-killing" climate regulations.

In a maiden trip to the Environmental Protection Agency, he ordered a review of emission limits for coal-fired power plants and eased restrictions on federal leasing for coal production.

Trump said the measures herald "a new era in American energy and production and job creation."

Environmentalists fear the steps may be a prelude to a US withdrawal from the landmark 2015 Paris climate accord and said the measures will make it difficult, if not impossible, for the US to meet its commitments under that agreement.

Curbing emissions from coal-fired power plants was a pillar of America's commitment to cut carbon emissions by 26-28 percent by 2025.

China "will honour its obligations 100 percent" regardless of whether other countries change their policies and "will not change its determination, its goals, and its measures regarding climate change", said Lu.

China is a signatory to the Paris accord, the first universal action plan for curbing global warming.

The US and China are together responsible for some 40 percent of the world's emissions, so their participation in the agreement is crucial for its success.

America's coal industry has long been in decline, with natural gas, cheap renewable energy, automation and tricky geology making the sooty fuel a less lucrative prospect.