The UN special representative on sexual violence in conflict says the abducted Nigerian schoolgirls "definitely" face the danger of being raped.
"My worry is those girls don't come back half of them pregnant," Zainab Hawa Bangura told a luncheon at the British Residence in New York on Friday.
She was meeting with editors, Tina Brown and the British ambassador to the US in preparation for a global summit next week in London on sexual violence in conflict. Angelina Jolie and British Foreign Secretary William Hague will co-chair.
The abduction of more than 300 schoolgirls by Boko Haram militants in April shocked the world and caused outrage among Nigerians. More than 200 girls remain captive.
Bangura says the international community needs to prepare the girls' families for their return.