Bandits had stormed the Bethel Baptist High School in the south of Kaduna State overnight and abducted 140 students.
The attack is the 10th mass school kidnapping since December in northwest Nigeria, which authorities have attributed to armed bandits seeking ransom payments.
However, Buhari, in a statement issued by his spokesman, Garba Shehu, expressed concern over attacks on Kaduna and Niger States, largely targeted at students.
Buhari said there is an ongoing deployment of additional security personnel to all troubled areas.
He urged security outfits to “act swiftly” to rescue all school boys and girls in the affected states and ensure safe return.
Buhari said the disturbing incidents of kidnapping students, mostly in Northern states, was already threatening to undermine efforts in boosting school enrollments in states that were adjudged educationally backward.
He called on state governments to ensure compliance with UN-supported Safe Schools Programme, which the administration had adopted.
The President described kidnapping as cowardly and despicable, condemning it as an assault on affected families