The U.S. will send a team of experts overseas to help Nigeria deal with the growing crisis involving kidnapped girls. White House spokesman Jay Carney called the abductions horrific and said time is of the essence.

Secretary of State John Kerry said the U.S. is deeply concerned about the welfare of the young girls. An Islamist militant group is claiming responsibility for abducting more than 200 schoolgirls and vows to sell them as slaves.

The United Nations has warned the group that such an action would be considered a crime against humanity.

State Department spokeswoman Jen Psaki said the U.S. team would likely include law enforcement officials and military personnel. Carney called it an advisory team and said a more active military role is not being considered at this time.

Secretary Kerry said members of the U.S. team will have experience in criminal investigations and hostage negotiations.

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