UN humanitarian chief Stephen O’Brien on Saturday told the Security Council that the world is facing the worst humanitarian crisis since the organisation’s inception in 1945. He urged the member nations to provide immediate funding “to avert a catastrophe.” The UN official said around 20 million people in Yemen, South Sudan, Somalia and northeast Nigeria are facing starvation and famine.

“To be precise we need $4.4 billion (approximately Rs 29,000 crore) by July,” O’Brien said. He added that “without collective and coordinated global efforts, people will simply starve to death.”

After his visit to Yemen, O’Brien said the conflicting Shia Houthi rebels and government factions were denying people access to humanitarian aid. “They must be held accountable for the inevitable famine, unnecessary deaths and associated amplification in suffering that will follow,” AP quoted him as saying. He said Secretary-General Antonio Guterres will chair a pledging meet to generate funds for Yemen on 25 April in Geneva.

Calling the famine in South Sudan man-made, O’Brien said the world’s newest nation is reeling from the effects of the three-year civil war. “Parties to the conflict are parties to the famine – as are those not intervening to make the violence stop.” The official, who also visited South Sudan, warned of a rise in cholera cases.

On the Somalian crisis, he said a famine could be averted. “Women and children walk for weeks in search of food and water,” O’Brien said. He said the UN and its partners are better equipped to address the situation with increased control over resources, a better network and stronger partnership with the new Somalian government.

The UN has described the situation in north-eastern Nigeria as the “greatest crisis on the continent” with its magnitude being revealed with the decreasing influence of militant group Boko Haram. The group’s retreat has revealed large-scale displacement, mass killings, and famine-like conditions affecting people in the thousands.