In this photo taken Friday, March 10, 2017, women pick leaves from a tree that they will later cook for dinner in the small village of Apada, near Aweil, in South Sudan. The world's largest humanitarian crisis in 70 years has been declared in three African countries on the brink of famine, just as President Donald Trump's proposed foreign aid cuts threaten to pull the United States back from its historic role as the world's top emergency donor. (Mackenzie Knowles-Coursin/UNICEF via AP)
In this photo taken Friday, March 10, 2017, women pick leaves from a tree that they will later cook for dinner in the small village of Apada, near Aweil, in South Sudan. The world's largest humanitarian crisis in 70 years has been declared in three African countries on the brink of famine, just as President Donald Trump's proposed foreign aid cuts threaten to pull the United States back from its historic role as the world's top emergency donor. (Mackenzie Knowles-Coursin/UNICEF via AP) Credit: Mackenzie Knowles-Coursin

Nairobi, Kenya — The world’s largest humanitarian crisis in 70 years has been declared in three African countries on the brink of famine, just as President Donald Trump’s proposed foreign aid cuts threaten to pull the United States from its historic role as the world’s top emergency donor.

If the deep cuts are approved by Congress and the U.S. does not contribute to Africa’s current crisis, experts warn that the continent’s growing drought and famine could have far-ranging effects, including a new wave of migrants heading to Europe and possibly more support for Islamic extremist groups.

The conflict-fueled hunger crises in Nigeria, Somalia and South Sudan have culminated in a trio of potential famines hitting almost simultaneously. Nearly 16 million people in the three countries are at risk of dying within months.

Famine already has been declared in two counties of South Sudan and 1 million people there are on the brink of dying from a lack of food, U.N. officials have said. Somalia has declared a state of emergency over drought and 2.9 million of its people face a food crisis that could become a famine, according to the U.N. And in northeastern Nigeria, severe malnutrition is widespread.

Trump’s proposed budget would “absolutely” cut programs that help some of the most vulnerable people on Earth, Mick Mulvaney, the president’s budget director, told reporters last week.