Mrs Kalu died at the age of 61, the senator says.

President Muhammadu Buhari has condoled with the Chief Whip of the Nigerian Senate, Orji Kalu, over the death of his wife, Ifeoma Kalu.

Mr Kalu, who represents Abia North District, announced his wife's death in a statement on Monday.

Mrs Kalu died at the age of 61, the senator said.

Mr Kalu, in the statement posted on his verified Facebook page, described the late Ifeoma as "a woman of virtue who was committed to the service of God and humanity."

He said a memorial service in honour of his late wife was scheduled to be held in United States of America.

"Please, remember her and loved ones in prayers at this difficult period," the senator appealed.

"May her gentle soul rest in perfect peace. Amen," he added.

Buhari's condolences

Reacting in a statement on Monday by his spokesperson, Femi Adesina, Mr Buhari, while commiserating with Mr Kalu over the loss, asked him and his family members to have trust in God for comfort and care in their "very difficult period of pain and deep reflection."

"President Buhari believes that the testimonies of the late wife's fear of God and charity should provide strength for the family, knowing that she lived well, and served the will of the Almighty," the statement read in part.

"The president prays for repose of her soul, and fortitude for the family to bear the loss," it added.

Mr Kalu, a former governor of Abia State, got married to Ifeoma, a medical doctor, in December 1989.

The couple has four children.

The death of Mrs Kalu comes about a month after her husband won re-election.

Mr Kalu, a member of the All Progressives Congress (APC), had polled 30, 809 votes to defeat his closest challenger, Nnamdi Iroh of the Labour Party, who scored 27, 540.

Since winning the Senate seat, Mr Kalu has been campaigning to become the next Senate President of Nigeria and has asked President Buhari to prevail on the APC leadership to zone the position to the South-east, where he hails from.