A abnormally strong El Niño weather pattern and extreme droughts have left millions of Africans vulnerable to hunger, water shortages and disease, a United Nations agency warned on Wednesday, including about 1 million severely malnourished children who need treatment.

The U.N. Children’s Emergency Fund, or UNICEF, said those children are located in Eastern and Southern Africa, where the extreme weather has adversely affected food supplies. It said families there have skipped meals or sold some of their possessions to cope with rising prices.

In a statement, Leila Gharagozloo-Pakkala, the agency’s regional director for Eastern and Southern Africa, called the situation “unprecedented” and warned of a long-lasting effect.

“The El Niño weather phenomenon will wane, but the cost to children – many who were already living hand-to-mouth – will be felt for years to come,” Gharagozloo-Pakkala said.

Meteorologists have said this season’s El Niño is one of the strongest on record and its effects are likely to continue well into 2016. However, the U.N. Office for Humanitarian Affairs has estimated that areas affected by the El Niño-fueled drought will likely need two years to recover.

El Niño occurs when part of the Pacific Ocean is warmer than usual, setting off a ripple effect that brings atypical and often extreme weather throughout the world. It has been blamed for creating droughts in some nations and floods in others, both of which can destroy harvests.

Last week, four agencies issued a joint statement warning the weather pattern could devastate Southern Africa’s upcoming harvests. The World Food Programme, Food and Agricultural Organization, Famine Early Warning Systems Network and European Commission’s Joint Research Centre said parts of Southern Africa are in the midst of their driest season in 35 years, with Zimbabwe, Lesotho and many South African provinces declaring drought emergencies.

Other nations have implemented measures to reduce water consumption because of low levels.

Two of the harder-hit nations are South Africa and Malawi, and the agencies said maize prices surged to record-high levels in those countries. The agencies warned the window of opportunity to plant crops in Southern Africa had nearly closed, and forecasts point to another poor harvest.

“Over the coming year, humanitarian partners should prepare themselves for food insecurity levels and food insecure population numbers in southern Africa to be at their highest levels since the 2002-2003 food crisis,” the agencies warned, saying it was too early for an exact figure.

Any increase would add to the millions of people who currently need food aid.

That includes more than 10 million Ethiopians, a total UNICEF says could reach 18 million by December. The agency says children have skipped school because they have to search for water.

UNICEF says about 2.8 million people are at risk of going hungry in Malawi, while food insecurity poses an issue for 2.8 million Zimbabwe residents and 800,000 people in Angola.

El Niño has also brought heavy rains to Kenya, which UNICEF says is fueling cholera outbreaks.

The World Food Programme also recently said El Niño has hurt Haiti’s agriculture industry.

The weather isn’t the only the thing impacting people’s ability to secure food.

Violent conflicts have spurred food shortages in other nations, and the Famine Early Warning Systems Network says “emergency” conditions now exist in parts of South Sudan and Yemen.