“Girls should go to school,” UN Secretary-General António Guterres called on Afghanistan’s Taliban rulers on Friday to allow teenage girls to resume secondary education.

“Afghan girls continue to be locked out of classrooms,” he said on Twitter late Friday.

Since regaining power a year ago, Islamist groups have banned schools in most Afghan provinces from returning to school for girls above grade 6. The Taliban called this a temporary suspension, but refused to lift the ban despite international pressure.

“This is an unjust violation of the right to equality that damages the whole country. Girls go to school.” Guterres on Twitter.

Critics say the ban denied access to education for an entire generation in Afghanistan, with devastating consequences for high school girls and their families.

When the Taliban were in power from 1996 to 2001, they completely banned girls’ education.

Hardline rebel groups took control of Afghanistan last August, pulling out all US-led foreign forces and ending nearly two decades of war with the Taliban. Internationally recognized government security forces collapsed in the face of nationwide riot attacks.

Although the Taliban brought security to much of Afghanistan, their restrictions on women’s rights and civil liberties sparked global condemnation and led to the country’s international isolation.

Taliban leaders defended their policies and restrictions on women as in line with Afghan culture and Sharia, or Islamic law, and dismissed international calls for reform as interference in Afghanistan’s internal affairs.

An already deep humanitarian crisis and growing economic turmoil stemming from the Taliban takeover have pushed most of the country’s estimated 40 million impoverished people into even greater poverty.

New Afghanistan Envoy

Mr. Guterres announced late Friday that he had appointed former Kyrgyzstan President Roza Otunbayeva as his new special envoy for Afghanistan. She will replace Deborah Lyons of Canada as head of the United Nations Assistance Mission in Afghanistan, known as UNAMA.

Otumbayeva will oversee UN humanitarian operations and dealings with the Taliban. She served as President of Kyrgyzstan from 2010 until 2011.

The United Nations Humanitarian Director Martin Griffiths told the Security Council on 29 August that Afghanistan faces increasing poverty, with 6 million people attributed to humanitarian, economic, climate and financial crises. warned that they were suffering from severe food shortages.

Griffiths said he was “worried” that those numbers would deteriorate quickly, as winter weather has spiked already high fuel and food prices.