Why Sambisa forest hasn't been liberated by the military-NSA

 To mark the one year anniversary of the abducted Chibok girls, the National Security Adviser (NSA) Col. Sambo Dasuki has reassured Nigerians that the girls will be rescued and Sambisa Forest ,the stronghold of Boko Haram,will be liberated before May 29.
In a statement , the NSA said,

“Right now, all Boko Haram camps, except Sambisa Forest have been destroyed. The forest would have since been liberated but for the unfavourable weather condition prevailing in the area as all needed reconnaissance activity and necessary deployment of troops have been made for the operation. ”
“Every movement of the terrorists is being monitored and every necessary detail is being taken care of to rid the country of the last bastion of terrorists’ infestation”.

“Aside the Chibok girls, other Nigerian girls, boys, men and women were abducted by the terrorists and all efforts are being made to rescue them all.”“President Jonathan had already given his words to all the security and service chiefs before the election that he would abide by the decision of Nigerians. At the meeting, he also told them to perform their duties professionally during the polls.

“While we anticipated that he would congratulate his opponent if the result is announced in favour of opposition candidate, he gratuitously without prompting of anyone conceded defeat to the surprise of all.