Mark Lowcock, head of the world body's Office for the Coordination of Humanitarian Affairs, spoke to The Associated Press on Monday after laying out the organization's 2019 humanitarian appeal.
OCHA says $21.9 billion is needed next year for food, shelter, health care, education, protection and other assistance worldwide. It predicts nearly 132 million people in 42 countries will need assistance.
The worst humanitarian crisis is in Yemen, where the government and a Saudi-led coalition have been locked in a largely stalemated war with the Iran-aligned Houthi rebels since March 2015. The fighting has claimed tens of thousands of lives and pushed the country to the brink of famine.
The executive director of the U.N.'s World Food Program, David Beasley, meanwhile said an upcoming report on hunger levels in Yemen will show a sharp increase. "We're seeing the severe hunger rate spike from 8 million to 12 million (people)," he said.
"I've heard many say that this is a country on the brink of catastrophe," Beasley said. "This is not a country on the brink of a catastrophe. This is a country that is in a catastrophe."
"Let's hope that these peace talks that start tomorrow or the day after will yield to a path forward to providing some hope for the children of this country," he added.
OCHA's Lowcock said the "onus" in the peace talks is on Yemen's government and the Houthi rebels to "take this seriously and act in a responsible way."
The two sides are set to meet later this week following a series of confidence-building measures. Around 50 wounded rebel fighters were flown to Oman for treatment on Monday, meeting a key Houthi demand. On Tuesday, Abdul-Qader el-Murtaza, a rebel official, said the government and the coalition have agreed to a U.N.-brokered prisoner exchange approved by the Houthis.
Houthi delegates flew to Stockholm from Yemen's rebel-held capital, Sanaa, on Tuesday. Other rebel delegates were expected to travel to Sweden from Oman on Wednesday. The U.N. says both sides have agreed to attend the talks.
Sweden's deputy U.N. ambassador, Carl Skau told, reporters at U.N. headquarters in New York that the Houthi delegation arrived in Stockholm late Tuesday. He said the Yemeni delegation was due shortly, and talks would begin before the end of the week.
David Miliband, president of the International Rescue Committee, on Tuesday urged the U.S. and Britain to use their influence as military supporters of the Saudi-led coalition to "encourage meaningful dialogue in these talks."
"It's time for world leaders to listen to their constituents and help end the unmitigated suffering of the Yemeni people," he said in a statement.
A survey commissioned the IRC found that 75 percent of Americans oppose U.S. weapons sales to Saudi Arabia and the United Arab Emirates, a leading member of the coalition.
The YouGov survey showed that 82 percent believe Congress should vote to end or decrease arms sales to the two Gulf Arab countries.
YouGov surveyed 1,168 respondents online from Nov. 7 until Nov. 9. The poll had a margin of error of 3.3 percent, IRC said.
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