Until Donald Trump took office as president for the second time at the beginning of the year, the US aid agency USAID accounted for over 40 percent of the world's total financing of humanitarian aid.
After the inauguration, thousands of aid and development programs around the world have been terminated, which can lead to the death of many millions of people, according to the study published in the British medical journal The Lancet.
Of the more than 14 million estimated deaths, described as avoidable, 4.5 million are children under 5 years, according to the study.
The cuts "risk abruptly stopping - and even reversing - two decades of progress in health among vulnerable populations", warns one of the study's authors, Davide Rasella at the Spanish research institute IS Global.
