The top UN humanitarian official welcomed the start of a ceasefire in Yemen aimed at allowing the delivery of relief and aid to Yemen. "I call on all parties to the conflict to respect this vital pause in hostilities," Undersecretary General for Humanitarian Affairs Valerie Amos said in a statement late Tuesday. "This pause will provide a respite for civilians and allow the delivery of food, medical supplies, and other essential items to people who have been trapped in conflict zones." Amos, who also is the UN emergency relief coordinator, stressed that aid not be given to one Yemeni group over another. "Given the role of the United Nations in coordinating emergency relief activities in an impartial and neutral way, I request that humanitarian assistance to Yemen be routed through existing UN and international humanitarian organization channels," Amos wrote.