The office of the United Nations Humanitarian Coordinator said the decision to open the offices was a result of the difficulties it faced in Ibb The UN appealed for $21.9 billion to address 21 humanitarian crises worldwide next year The United Nations continues in its push to improve the delivery of humanitarian aid with the opening of two offices in the Yemeni province of Taiz, Saudi state news agency SPA reported. The office of the United Nations Humanitarian Coordinator said the decision to open the offices was a result of the difficulties it faced in Ibb. The UN appealed for $21.9 billion on Tuesday to address 21 humanitarian crises worldwide next year, including $4 billion for Yemen, its largest aid operation. UN aid chief Mark Lowcock has warned last week that Yemen was “on the brink of a major catastrophe.” Wrapping up his trip, Lowcock said conditions had deteriorated alarmingly since his last visit in October 2017. “In Aden, I met emaciated children so malnourished they could barely open their eyes,” Lowcock said in a statement. “Humanitarian assistance helps many of these children recover. But I also heard heartbreaking stories of children relapsing again and again because their families simply can"t afford food or proper medical care." The United Nations has termed Yemen the world"s worst humanitarian crisis.