"If this would come to pass, this will be another horrendous step backward for the people of Afghanistan and especially for women and girls," said UN spokesperson Stephane Dujarric.
"Our colleagues in Kabul are speaking to the de facto authorities. We're trying to ascertain exactly what is being planned. We have not gotten anything official."
"Every person has a right to an education, and we want to make sure that the de facto authorities guarantee access to education for children and young adults," he added.
It is the latest restriction in the country after the Taliban decree in December 2022 that banned Afghan women from working for NGOs.
The Taliban's return to power in Afghanistan on Aug. 15, 2021, followed by the disruption of international financial assistance has left the worn-torn country in economic, humanitarian and human rights crises.
Taliban rulers have mounted a sustained attack on human rights despite their commitments to protect human and women's rights.
Women and girls have been deprived of their rights, including the right to education, and disappeared from public life under the Taliban.
Thousands of women have since lost their jobs or were forced to resign from government institutions and the private sector.