This is coming after the army failed in its initial 40-day ultimatum to capture the terrorist.
This was disclosed by Theatre Commander, Operation Lafiya Dole, Major General Ibrahim Attahiru, during a press briefing about the army's ongoing war with the terrorist group on Wednesday, August 30, 2017.
On July 21, Chief of Army Staff, Lieutenant General Tukur Buratai had charged the theatre to deliver Shekau dead or alive within 40 days.
That ultimatum expired on Wednesday, and a reporter at the briefing asked the commander about what that means for the army.
In response, Maj-Gen Attahiru said the ultimatum was not the sole objective of the army and that it's something that could always be extended until Shekau is caught.
He said, "The 40-day ultimatum given to the theatre is concomitant task to the overall objectives for which the theatre stands to achieve. The theatre is here to deal a decisive blow to Boko Haram.
"That being the case, capturing Shekau is an enhancer to that objective. 40 days was a guideline.
"It does not mean that because 40 days is about to elapse and Shekau has not been captured, we'll renew other 40 days, and we'll go after him and get him."
Shekau has eluded capture from the military ever since Boko Haram's bloody insurgency started in 2009.
The army has claimed on several occasions that it had killed the leader of the largest faction of the terrorist organisation, but there has been no conclusive proof to back it up.
The group's insurgency in the northern region has resulted in the death of over 20,000, and displaced over 2 million people.