The nomination of Musa is the latest military leadership shake-up as the Nigerian armed forces face a tumultuous few weeks, and comes as Africa's most populous country undergoes intense criticism for the handling of its myriad conflicts.

The country faces a long-running jihadist insurgency in the northeast, while armed "bandit" gangs conduct kidnappings and loot villages in the northwest and farmers and herders clash in the country's centre over dwindling land and resources.

Musa had been serving as chief of defence staff until October, when Tinubu sacked a slew of the country's top military brass following media reports of a coup attempt.

The administration officially denied the reports of a coup plot, though military, intelligence and government sources told AFP that there had been a foiled plot to oust the country's civilian leaders and install a junta.

Weeks later, the west African country was hit by a wave of mass kidnappings, including of hundreds of schoolchildren.

While such abductions for ransom are common in the country, the sharp uptick saw Tinubu declare a "nationwide security emergency".

Separately, Nigeria has faced a diplomatic offensive from the United States, which has alleged that Christians are being killed en masse.

On Monday, defence minister Mohammed Badaru Abubakar resigned, citing health reasons.

Musa will need to be confirmed by the Senate to take up his new post.

In a letter to the Senate, Tinubu "expressed confidence in General Musa's ability to lead the Ministry of Defence and further strengthen Nigeria's security architecture," according to a statement from the presidency.

- Hundreds of students kidnapped -

Since Boko Haram jihadists kidnapped nearly 300 schoolgirls from the northeastern town of Chibok in an infamous raid more than a decade ago, Nigeria has struggled to contain mass abductions.

But Washington's rhetoric about Christian persecution -- a framing rejected by the Nigerian government and independent security analysts who note the country's conflicts leave victims across religious lines -- has again placed the nation's security crisis under the spotlight.

With diplomatic tensions ongoing, the wave of kidnappings in November saw schoolchildren and teachers, worshippers and priests, a bride and her bridesmaids, farmers, women and children all taken hostage.

In the largest attack, armed gangs seized more than 300 teachers and staff at St. Mary's co-education school in north-central Nigeria on November 21. Fifty escaped, but the rest remain in captivity.

Nigerian authorities on Monday promised the pupils would be home "soon".