The UN food agency’s director urged the EU on Monday to help raise the $1 billion needed over the next few months to save hundreds of thousands of children from starving to death in Yemen and three African countries.

World Food Program Director David Beasley said 20 million people were “on the brink of famine” in Yemen, South Sudan, Somalia and Nigeria in the worst humanitarian crisis since 1945. “I’m here to appeal to the goodness of some of the wealthiest nations… to please continue to step up at a time such as this,” Beasley said after meeting EU foreign policy chief Federica Mogherini.

“I want the US to contribute more, the EU to contribute more,” he said. He appealed to wealthy EU countries like Britain, Germany and especially France to send more aid, saying Paris was contributing too little at $30 million. He said of the 20 million people facing famine, 5.7 million are children who are malnourished.