Hours after taking office, US president Donald Trump ordered a 90-day pause in US-funded global projects pending a review of their efficiency.
The directive excludes funding for emergency food programmes and military aid to Israel and Egypt.
It remains unclear whether this will impact on military support for Ukraine.
Joe Biden's administration had previously stepped up military aid to Ukraine, but there are now doubts over whether this will continue under the Trump administration.
The order has been criticised by humanitarian officials because it cuts funding to life-saving health programmes such as clinics and immunisation programmes.
This comes as humanitarian aid surges into the Gaza Strip following the ceasefire between Israel and Hamas, and amid famine in war-torn Sudan.
Abby Maxman, head of Oxfam America, warned suspending funding "could have life or death consequences" for children and families around the world.
"By suspending foreign development assistance, the Trump administration is threatening the lives and futures of communities in crisis, and abandoning the United States' long-held bipartisan approach to foreign assistance which supports people based on need, regardless of politics," she added.
Government-wide review
The order by US Secretary of State Rubio said the pause was necessary to ensure "appropriations are not duplicated, are effective, and are consistent with President Trump's foreign policy".
Standards for a review of all foreign assistance are expected to be set within the next month to ensure it is "aligned with President Trump's foreign policy agenda," a global cable said.
The government-wide review is expected to be completed within three months and a report will be produced for Mr Rubio to make recommendations to Mr Trump.
The US provides more foreign aid than any country around the world and budgeted around $60bn (€57bn), or 1% of the US budget in 2023.
Reporting via IRN.
Main image: President Donald Trump speaks after taking the oath of office during the 60th Presidential Inauguration in the Rotunda of the U.S. Capitol in Washington, Monday, Jan. 20, 2025. (Kenny Holston/The New York Times via AP, Pool)