The State Department cited "budget constraints" as it said it was ending the Air Quality Monitoring Program's transmission of data.

"The current budget climate requires us to make difficult cuts and, unfortunately, we cannot continue to publish this data," a State Department spokesperson said.

Historical data will remain on a site of the Environmental Protection Agency, but live data stopped Tuesday and will remain down unless funding is restored, the State Department said.

The United States since 2008 has monitored air quality through embassies -- as a service to Americans overseas but also, increasingly, as a way to share accurate scientific data that may otherwise be censored overseas.

In China, authorities in 2014 banned a popular app from sharing data from the US embassy ahead of a major international summit attended by then president Barack Obama.

But researchers say that the transparency has had a noticeable effect, with China taking action after being embarrassed by US embassy data released on social media that showed far worse pollution than official figures.

Obama's ambassador to China, Gary Locke, faced scorn in state media after he presided over the introduction of monitors at the embassy and consulates that tracked the so-called PM 2.5 particulate matter carried in the thick blankets of smog pervading China's capital.

The air quality data from the US embassy is also frequently used as a reference in New Delhi, which has severe pollution issues.

Trump since returning to office in January has slashed spending including on international cooperation and the environment as he vows to trim government and prioritize tax cuts.

Under the guidance of tech billionaire Elon Musk, the Trump administration has effectively shut down the US Agency for International Development, long at the forefront of US efforts for influence overseas.

Trump has also sharply reduced environmental staffing and turned back a slew of climate initiatives by previous president Joe Biden.

Air pollution, which is aggravated by climate change, contributes to nearly seven million premature deaths globally each year, according to the World Health Organization.