Sexual violence is being used as a weapon of war in Ethiopia's Tigray, the UN aid chief told the Security Council on Thursday, prompting the US envoy to challenge the body's silence, asking, "Do African lives not matter as much as those experiencing conflict in other countries?"

The UN official, Mark Lowcock, said the humanitarian crisis in Tigray had deteriorated over the past month with challenges to aid access and people dying of hunger. He said the world body had not seen any proof that soldiers from neighboring Eritrea - accused of massacres and killings in Tigray - have withdrawn.

"To be very clear: the conflict is...