Calling the kidnapping of hundreds of Nigerian schoolgirls "an outrage and a tragedy," White House press secretary Jay Carney on Monday said the U.S. is "doing what we can to assist the Nigerian government."
The White House spokesman also said the U.S. was also "working with the Nigerian government to strengthen its criminal justice system and increase confidence in the government by supporting its efforts to hold those responsible for violence accountable."
He added that he had not heard a request to send in U.S. special forces to search for the girls.
The leader of the Islamist militant group Boko Haram, Abubakar Shekau, has claimed responsibility for the kidnapping and said he plans to sell the children.
"I abducted your girls. I will sell them in the market, by Allah," he said in a video obtained by Agence France-Presse and translated by CNN. "There is a market for selling humans. Allah says I should sell. He commands me to sell. I will sell women. I sell women."
The U.S. designated Boko Haram as a foreign terrorist organization last year.
The mass kidnapping has sparked outrage across the world, with supporters adopting the Twitter hashtag #bringbackourgirls.
Carney said that, in addition to assistance on this case, the U.S. was looking to bolster Nigerian institutions more widely. Last year, the U.S. provided $3 million in aid to Nigeria, and FBI agents have assisted Nigerian authorities in investigating bombings there and training local police on basic forensic and police procedures.
"The U.S. also supports programs and initiatives that provide positive alternatives to communities most at risk of radicalization and recruitment, including through vocational training," Carney said.