UN Secretary-General Antonio Guterres said on Thursday that the humanitarian situation in Afghanistan had "deteriorated alarmingly" and urged donors to provide "unconditional and flexible funding" towards its $4.4 billion appeal for aid.

Opening a high-level pledging conference, he said the Afghan economy had all but collapsed since the Taliban takeover in August and nine million Afghans were at risk of famine. Families had sold children or organs to survive, he said.

He also called for the reopening of schools for all students in Afghanistan "without discrimination," after the Taliban's decision to ban girls from secondary education.