JOHANNESBURG (AP) — Nigeria's military is acknowledging a major attack against it by Islamic extremists after opposition lawmakers said 44 soldiers were killed.

The statement issued overnight doesn't say how many are dead after the Nov. 18 attack in Metele in the northeast. Nigeria is often reluctant to expose the toll of such attacks by Boko Haram extremists and fighters linked to the Islamic State group.

As pressure over insecurity builds on President Muhammadu Buhari ahead of next year's election, an aide on Saturday says Buhari has summoned military chiefs and sent the defense minister to neighboring Chad for an "urgent meeting" with President Idriss Deby. A multinational force combating Boko Haram is based in Chad.

Aide Bashir Ahmad says Nigeria's leader is "worried by Boko Haram's renewed attacks on military bases."