Note below from FNC Jennifer Griffin:
According to senior US officials with knowledge of the search for the Nigerian school girls:
The US believes that the group has been broken up into smaller groups and may or may not still be in Nigeria. These officials said they had no knowledge that the girls were divided specifically into 4 groups – that was more specific than they were prepared to go.
A senior US official says there is now some discussion about whether to send ISR (surveillance, aka drones) to help with the search. Again, this would need to be requested by the Nigerian government but there is discussion about the possibility of drones, according to this official.