The 16-year-old Pakistani student became one of the world's most recognizable education rights advocates when she survived an assassination attempt in 2012.
"These girls are my sisters," she told NBC News and urged world leaders to take action.
"We should all stand up together and we should speak," she said.
"I think they haven’t studied Islam yet, they haven’t studied Quran yet, and they should go and they should learn Islam," she said. "I think that they should think of these girls as their own sisters. How can one imprison his own sisters and treat them in such a bad way?"
Boko Haram has threatened to sell the abducted schoolgirls into slavery.
"There is a market for selling humans. Allah says I should sell. He commands me to sell. I will sell women. I sell women," alleged leader Abubakar Shekau said in a video.
Yousafzai has joined the international social media campaign, #BringBackOurGirls, calling on the Nigerian government to step up its rescue efforts.