Abuja, May 13 (RHC)-- The Nigerian government has already rejected a Boko Haram proposal to free the girls in return for the release of the militant group’s prisoners.

Boko Haram leader Abubakar Shekau floated the offer in a video on Monday. The Boko Haram’s video showed close to half of the nearly missing 300 girls. It was the first public image of the kidnapped schoolgirls since their abduction nearly one month ago.

In related news, the United States has begun flying piloted surveillance missions over Nigeria as part of the search efforts for the nearly 300 schoolgirls kidnapped last month. It is unclear how many planes are involved, but the State Department says it is providing "intelligence, surveillance and reconnaissance support," to the Nigerian government.

On Monday, a Nigerian official said the government is exploring "all options" to rescue the girls from captivity. The official said that Nigerian authorities are "interacting with experts, military and intelligence experts from other parts of the world."