More than 14 million additional deaths - some 4.5 million of them among children under the age of 5 - could occur over the next five years due to massive cuts in US foreign aid, according to a study published in The Lancet medical journal.
The research, led by scientists in Barcelona and Salvador da Bahia, Brazil, warns against ongoing reductions in aid initiated by the US President Donald Trump.
The team analysed mortality data from more than 130 countries and regions between 2001 and 2021, using the findings to forecast outcomes through 2030.
Their projections suggest that the steep decline in US aid could have catastrophic consequences, particularly in low- and middle-income countries.
The US has been the world's largest provider of humanitarian aid.
The researchers attribute significant global health gains to the United States Agency for International Development (USAID), estimating that its programmes helped prevent nearly 92 million deaths by 2021, including over 30 million children under 5.
Notably, they found USAID efforts contributed to a 65% reduction in HIV/AIDS-related mortality and a 51% drop in deaths from malaria.
"Our estimates show that, unless the abrupt funding cuts announced and implemented in the first half of 2025 are reversed, a staggering number of avoidable deaths could occur by 2030," the authors wrote in the paper released on Monday.
In many countries, "the resulting shock would be similar in scale to a global pandemic or a major armed conflict," they said.
