Twenty states had challenged the end of the programme, meant to make localities more resilient to natural disasters.

A federal judge has said the administration of United States President Donald Trump acted unlawfully in ending a programme aimed at helping communities become more resilient to natural disasters.

The Trump administration had targeted the Building Resilient Infrastructure and Communities (BRIC) programme as part of a wider effort to overhaul the Federal Emergency Management Agency (FEMA).

But on Thursday, US District Judge Richard Stearns ruled that the administration lacked the authority to end the grant programme. The decision came in response to a lawsuit filed by 20 states, the majority led by Democrats.

Stearns said the administration’s action amounted to an “unlawful executive encroachment on the prerogative of Congress to appropriate funds for a specific and compelling purpose”.

“The BRIC program is designed to protect against natural disasters and save lives,” Stearns wrote, adding that the “imminence of disasters is not deterred by bureaucratic obstruction”.

Stearns had previously blocked FEMA from diverting more than $4bn allocated to BRIC to other purposes.

Massachusetts Attorney General Andrea Joy Campbell was among the plaintiffs praising the decision.

“Today’s court order will undoubtedly save lives by preventing the federal government from terminating funding that helps communities prepare for and mitigate the impacts of natural disasters,” she said in a statement.

BRIC is the largest resiliency programme offered by FEMA, designed to reduce disaster-related risks and bolster efforts to recover quickly.

The programme is emblematic of efforts under FEMA to take preventive measures to prepare for natural disasters, as climate change fuels more extreme weather across the country.

According to the lawsuit, FEMA approved about $4.5bn in grants for nearly 2,000 projects, primarily in coastal states, over the last four years.

Upon taking office for his second term, Trump initially pledged to do away with FEMA, with the agency sitting at the crossroads of the president’s climate change denialism and his pledge to end federal waste.

Trump has since softened on his position amid pushback from both Republican and Democratic state lawmakers. He has said he plans to reform the agency instead.

In November, acting FEMA head David Richardson stepped down from his post. That came amid internal pushback over Richardson’s lack of experience and cuts to the agency.

In a letter in August, nearly 200 FEMA staffers warned the cuts risked compounding future disasters to a devastating degree.

Upon taking on the role in May, Richardson threatened he would “run right over” anyone who resisted changes to the agency.