President Donald Trump's administration has pulled out of the Paris climate accord and slashed environmental regulations, but on Earth Day Wednesday it pointed the finger at China.

On the 50th anniversary of the international day of environmental awareness, the Trump administration indicated the steady decline in US carbon emissions over the past decade.

Secretary of State Mike Pompeo noted that China, which has surpassed the United States as the top polluter, does not expect its emissions to plateau until 2030.

China is "offsetting the progress of countries all around the world in reducing global emissions," Pompeo told reporters.

He called on UN Secretary-General Antonio Guterres, who issued an Earth Day call for climate action, to take notice.

"I would urge Secretary Guterres to make sure we have the data right -- the facts right -- about who is actually delivering on the things that we all value," Pompeo said.

Carbon emissions, blamed for rising temperatures, fell some two percent in the US last year due mostly to declining consumption of coal, one of the dirtiest forms of energy, according to scientific surveys.

The decline came despite Trump's campaign promises to revive the coal industry.

The administration has been chipping away at regulations and this month dealt a major blow by weakening rules set under former president Barack Obama that would have compelled automakers to reduce pollution.

Under Trump, who frequently denounces scientists, the United States is the only country out of the Paris climate accord, which was negotiated by Obama.

China points to its heavy investments in renewable energy aimed at improving its dangerous air quality and reducing carbon intensity, although like many emerging economies it argues that it cannot cut emissions yet.

Guterres in his message warned that climate change posed a major danger to the world even as it is facing the coronavirus pandemic.

"Greenhouse gases, just like viruses, do not respect national boundaries," Guterres said.

"We must act decisively to protect our planet from both the coronavirus and the existential threat of climate disruption," he said.

The United States has gone on the offensive against China on a number of fronts, accusing the Asian power of failing to halt the spread of the COVID-19 coronavirus that has killed more than 180,000 people.

Swedish teenage climate activist Greta Thunberg in an Earth Day message said that action was not ultimately up to governments or businesses.

"It will come from the best available science and public opinion," she wrote on Twitter.