Andimi was abducted early January when the insurgents attacked Michika. The news of his death broke on Tuesday morning.
In a statement by Garba Shehu, senior special assistant to the president, quoted Buhari as describing the killing as “cruel, inhuman and deliberately provocative”.
He said the president expressed sorrow that the insurgents killed the religious leader while giving signals that they were willing to release him to third parties.
The president assured Nigerians that “terrorists will continue to pay a heavy price for their actions and would comprehensively be defeated by our determined armed forces”.
“President Buhari consoles the Christian community all over Nigeria, the government and people of Adamawa state and the Bishop’s family over the sad loss of the man of God.
“The president urged nations of the world to end all support provided to Boko Haram and Islam in West Africa, ISWA terrorist groups whose only goal is to sow death, violence, and destruction in the sub-region.”