"We don't have independent information from the United States to support" that statement, US State Department spokeswoman Jen Psaki told reporters. "We, as a matter of policy and for the girls' safety and wellbeing, would not discuss publicly this sort of information regardless."
(READ MORE: West Africa leaders vow to wage "total war" on Boko Haram)
Nigerian Chief of Defence Staff Air Marshal Alex Badeh said on Monday that the country's military knew the location of the schoolgirls, abducted by the Boko Haram Islamic militant group on April 14.
Five US and European security officials, who spoke on condition of anonymity, said they had no credible information on the location of the girls and were skeptical that the Nigerian government knew where they were.
The five officials said the United States and some European allies had provided technical intelligence, including information from spy aircraft and satellites, to Nigerian authorities, who lack such intelligence capabilities.
But the officials said that as far as they knew technical intelligence systems had not produced precise or credible information establishing the girls' location.
The five officials said that if the Nigerians had obtained such information from informants on the ground, it has not been shared with US and allied agencies.
One impediment to finding the girls, the officials said, was that since their abduction seven weeks ago they had been divided into small groups. Boko Haram is also believed to be hiding them in densely forested terrain where it would be hard for modern technical intelligence systems to gather information.