Nigerian leader asks UN to help free abducted Chibok Girls

FILE- In this Wednesday, Sept. 21, 2016 file photo Nigerian President Muhammadu Buhari meets United Nations General Secretary-General Ban Ki-moon at U.N. Headquarters in New York City, NY, USA Nigeria's President Muhammadu Buhari has invited the United Nations to help negotiations to swap of the kidnapped schoolgirls from Chibok for detained leaders of Boko Haram, a government statement said Thursday Sept. 22, 2016. (AP Photo/Mary Altaffer, File) (The Associated Press)

FILE- In this undated image file image taken from a video distributed Sunday, Aug. 14, 2016, shows an alleged Boko Haram soldier standing in front of a group of girls alleged to be some of the 276 abducted Chibok schoolgirls held since April 2014, in an unknown location. Nigerian President Muhammadu Buhari is inviting the United Nations to help negotiations to swap the kidnapped schoolgirls from Chibok for detained leaders of the Boko Haram Islamic extremist group. A government statement said Buhari's offer is a "show of commitment" made to U.N. Secretary General Ban Ki-moon Wednesday Sept. 21, 2016, on the sidelines of the U.N. General Assembly in New York. (Militant video/Site Institute, File via AP) (The Associated Press)

FILE- In this Tuesday, April. 14, 2015 file photo, young girls known as Chibok Ambassadors, carry placards bearing the names of the girls kidnapped from the government secondary school in Chibok, two years ago, during a demonstration, in Abuja, Nigeria. Nigerian President Muhammadu Buhari is inviting the United Nations to help negotiations to swap the kidnapped schoolgirls from Chibok for detained leaders of the Boko Haram Islamic extremist group. A government statement said Buhari's offer is a "show of commitment" made to U.N. Secretary General Ban Ki-moon Wednesday Sept. 21, 2016, on the sidelines of the U.N. General Assembly in New York. AP Photo/Sunday Alamba File) (The Associated Press)

Nigerian President Muhammadu Buhari is inviting the United Nations to help negotiations to swap the kidnapped schoolgirls from Chibok for detained leaders of the Boko Haram Islamic extremist group.

His government has been criticized by parents of the abducted students, community leaders and human rights activists for failing to free the Chibok girls. The mass abduction of 276 girls in April 2014 incited outrage around the world. Dozens escaped but 217 remain missing.

A government statement said Buhari's offer is a "show of commitment" made to U.N. Secretary General Ban Ki-moon Wednesday on the sidelines of the U.N. General Assembly in New York.

Buhari told Ban that finding credible Boko Haram leaders for the negotiations has been made more difficult by an ongoing leadership struggle among the extremists.