The U.S. ambassador to the United Nations is calling for an impartial investigation into the way that child sexual abuse allegations against French soldiers in the Central African Republic have been handled. Meanwhile, the U.N. human rights chief is asking why France didn't move more quickly to pursue the claims.

The U.N. high commissioner for human rights, Zeid Raad al-Hussein, made his first public comments Friday on the case since it was first reported late last month.

Questions remain about why it took several months for U.N. and French investigations to come to light and where the accused French soldiers are now.

U.S. Ambassador Samantha Power told reporters that the allegations are "completely horrific" and said that "when allegations like these are made, speed is essential."