The United States is sending a team of experts to Nigeria to help in the search for more than 250 kidnapped school girls.
State Department spokeswoman Jen Psaki says President Goodluck Jonathan has accepted the U.S. offer, following talks by phone on Tuesday with Secretary of State John Kerry.
In a briefing, Psaki also said the U.S. embassy in Abuja was prepared to send a "coordination cell" that would include U.S. military personnel and law enforcement officials.
"An interdisciplinary team, and this is what they discussed on the call, that could provide expertise on intelligence, investigations, and hostage negotiations, help facilitate information sharing, and provide victim assistance."
On Monday, the Islamist militant group Boko Haram released a video saying it was responsible for the mid-April abduction of several hundred girls from their secondary school in Chibok, a town in the northern Borno state region.
More than 300 girls were kidnapped. Some managed to escape but 276 remain missing.
Earlier Tuesday, residents in another northern Nigeria village said suspected Boko Haram militants had kidnapped eight more girls in the region.
The residents of Warabe said Tuesday that gunmen stormed their village Sunday and kidnapped the girls. They say the kidnappers, who were in several vehicles, also took food and livestock during the raid.
In the video released Monday, Boko Haram leader Abubaker Shekau said, "I abducted your girls," and vowed to, in his words, sell them in the market.
The United Nations human rights office has warned Islamist militants they could face charges of crimes against humanity if they carried out the threat to sell the kidnapped girls.
In a Tuesday briefing, a spokesman for U.N. rights chief Navi Pillay said under international law, it would be "one of the most serious crimes" that exists. The spokesman also said those responsible for such a crime could be arrested, prosecuted and "jailed at any time in the future."
Also Tuesday, Britain said it was supporting the Nigerian government's efforts to find the girls.
British Foreign Secretary William Hague said his government is offering "practical help" to Nigeria.
"What has happened here with the actions of Boko Haram in using girls as the spoils of war, the spoils of terrorism is disgusting, it is immoral; it should show everybody across the world that they should not give any support to such a vile organization."
Some Nigerians have been critical of the government, saying President Jonathan's administration has not done enough to secure the girls' release. In a VOA interview , ruling People's Democratic Party spokesman Abdullahi Jalo said Mr. Jonathan is doing everything possible.
"He reaffirmed to people that no matter what, the government will spend its last blood, its last effort to see that these people, these girls, are returned to their loved ones."
During a televised appearance on Sunday, President Jonathan said he had ordered his top security officials to do all they could to secure the girls' release.
Unconfirmed reports say some of the girls have been "married" to their captors, while others allegedly have been moved across the border into Cameroon and Chad.