United States President Donald Trump’s administration has frozen funding for a wide range of federal programmes, in a move that experts say could potentially disrupt education, healthcare, poverty reduction and disaster relief schemes.

Officials said the decision, which is scheduled to take effect at 5pm EST (22:00 GMT) on Tuesday, was necessary to ensure that all funding complies with Trump’s priorities, including his crackdown on diversity, equity and inclusion (DEI) initiatives.

The Office of Management and Budget, which oversees the federal budget, said in a memo that the freeze included any money intended “for foreign aid” and for “nongovernmental organizations”, among other categories.

The White House said the pause would not impact Social Security and Medicare payments nor “assistance provided directly to individuals”.

That means some food aid programmes for the poor would not be affected, sources told the Reuters news agency.

But the funding freeze could affect trillions of dollars, at least temporarily, and cause potential interruptions in healthcare research, education programmes and other initiatives. Even grants that have been awarded but not spent are supposed to be halted.

Already on Tuesday, state agencies and early education centres appeared to be struggling to access money from Medicaid — a low-income healthcare programme — and Head Start, a scheme that provides early childhood support.

Four groups representing non-profits, public health professionals and small businesses filed a lawsuit on Tuesday challenging Trump’s directive, saying it “will have a devastating impact on hundreds of thousands of grant recipients”.

“From pausing research on cures for childhood cancer to halting food assistance, safety from domestic violence, and closing suicide hotlines, the impact of even a short pause in funding could be devastating and cost lives,” Diane Yentel, the president and CEO of the National Council of Nonprofits, said in a statement.

Her group was among the four groups involved in Tuesday’s lawsuit.

Democratic state attorneys general also pledged to fight the order in court.

That includes New York Attorney General Letitia James, who said she planned to ask a Manhattan federal court to block the Republican president’s moves.

“My office will be taking imminent legal action against this administration’s unconstitutional pause on federal funding,” James said on social media. “We won’t sit idly by while this administration harms our families.”

Maxwell Alejandro Frost, a Democratic congressman from Florida, also said in a social media post on Tuesday afternoon that his team had been on the phone with multiple agencies and organisations that have been “completely cut off from federal money”.

“We’re talking housing, homeless services, public safety,” he wrote, warning that the freeze “could have drastic local impacts”.

We’ve been on the phone with multiple agencies/orgs. They’ve been completely cut off from federal money. We’re talking housing, homeless services, public safety, etc.

I’m calling a press conference today to explain how this could have drastic local impacts to our constituents.

— Maxwell Alejandro Frost (@MaxwellFrostFL) January 28, 2025

Senate Democratic Leader Chuck Schumer said the Trump administration did not have the authority to prevent spending approved by the US Congress.

“This decision is lawless, destructive, cruel,” Schumer said in a speech to the Senate. “It’s American families that are going to suffer most.”

The US Constitution gives Congress control over spending matters, but Trump said during his campaign that he believes the president has the power to withhold money from programmes he dislikes.

Congressman Tom Emmer, one of the top Republicans in the House of Representatives, said Trump was simply following through on his campaign promises.

“You need to understand he was elected to shake up the status quo. That is what he’s going to do. It’s not going to be business as usual,” Emmer told reporters at a Republican policy retreat in Miami.

White House spokeswoman Karoline Leavitt also defended the administration’s decision, telling reporters on Tuesday afternoon that Trump and his team were acting as “good stewards of taxpayer dollars”.

“This is not a blanket pause on federal assistance and grant programmes from the Trump administration. Individual assistance that includes … Social Security benefits, Medicare benefits, food stamps, welfare benefits, assistance that is going directly to individuals, will not be impacted.”

Leavitt said the freeze “means no more funding for illegal DEI programmes” or for “the Green New Scam”, a term Trump and his allies have used to describe measures taken by former President Joe Biden to address the climate crisis.

“It means no more funding for transgenderism and wokeness across our federal bureaucracy and agencies,” she said.

The Office of Management and Budget memo is the latest directive in Trump’s push to dramatically reshape the federal government, the country’s largest employer, since he took office on January 20.

Trump has taken dozens of executive actions since the start of his second term, including shuttering DEI programmes and imposing a federal hiring freeze.

Last week, the president also signed an executive order directing all federal government agencies to enact a 90-day pause on foreign assistance and to review existing programmes.

Days later, the US State Department said in a memo that it was suspending almost all new funding for foreign aid programmes with exceptions for the country’s top Middle East allies, Israel and Egypt.

As part of that aid suspension, the administration has moved to stop the distribution of drugs for HIV, malaria and tuberculosis, as well as medical supplies for newborn babies, in countries supported by the United States Agency for International Development (USAID).

The US is the largest single donor of aid globally, disbursing $72bn in 2023.