Strained by a year of multiple wars and mass refugee migrations, the United Nations is making the largest humanitarian appeal in its 70-year history.

The organization and affiliated agencies are seeking $20.1 billion in funding to help some 87 million people in 37 different regions and countries next year.

UN Seeks Record $20.1 Billion for Humanitarian Aid

"Suffering in the world has reached levels not seen in a generation," said the U.N.'s humanitarian aid chief, Stephen O'Brien.

UN Seeks Record $20.1 Billion for Humanitarian Aid

The U.N. agencies for health, refugees and humanitarian assistance – known as WHO, UNHCR and OCHA – said Monday that needs are greatest in Syria, Iraq, South Sudan and Yemen. Great need is expected to persist in those war-ravaged countries next year and is likely to grow elsewhere with disruptive El Nino weather patterns predicted for 2016.

UN Seeks Record $20.1 Billion for Humanitarian Aid

The agencies already are being squeezed in their efforts to deliver aid. They sought $19.9 billion in their 2015 appeals but face a record funding gap of $10.2 billion.

Governments supply most of the money in the U.N.'s annual appeal. The funds are used to buy food, shelter, medicine and other basic needs for vulnerable populations.