"Afghans have the right to live in peace, go to school, and play. So this is the message of Afghan girls right now," Yousafzai said as she stood alongside the top American diplomat.
"And we want to see a world where all girls have access to safe and quality education. And we hope that the U.S., together with the U.N., will take immediate actions to ensure that girls are allowed to go back to their schools as soon a possible," she said.
The Taliban who control Afghanistan had previously barred women from schools.
After re-asserting control over Afghanistan earlier this year, the Taliban said they will permit older girls to resume classes once they create a curriculum in line with their view of Islamic law.
Yousafzai was awarded the Nobel Peace Prize for her campaign for girls' education, after she survived being shot at the age of 15 by a Taliban gunman in her native Pakistan.