Meanwhile, a top U.N. official said U.S.-backed, Saudi-led airstrikes are exacerbating Yemen’s humanitarian catastrophe. U.N. Emergency Relief Coordinator Stephen O’Brien spoke to reporters while touring southern Yemen.

Stephen O’Brien: “The best humanitarian solution for all the Yemeni people is the conflict stops, the guns fall silent. That’s the best. And in the meantime, we have to do everything we can to support the people who have needs of food, of water, of warmth and of medicines. And we need to also make sure that we do everything we can to protect civilians from the terrible threat of war and all the terrible abuses that go on.”

O’Brien called for an end to a Saudi blockade of Yemen’s ports to allow food and medicine to arrive. The U.N. warns some 14 million Yemenis are hungry and at risk of famine.