Mr Femi Adesina, the president's spokesman, said Buhari gave the assurance on Tuesday in Abuja while receiving in audience former Vice President Namadi Sambo who heads the ECOWAS Election Mission to the West African country.

The Nigerian leader applauded President Mahamadou Issoufou for not attempting to tamper with the constitution of his country and elongate his stay in power after serving for the maximum two terms.

He said, "I come from Daura, few kilometers to Republic of Niger, so I should know a bit about that country.

"The president is quite decent, and we are regularly in touch. He is sticking to the maximum term prescribed by the constitution of his country.

"Also, we share more than 1,400 kilometers of border with that country, which can only be effectively supervised by God. I will speak with the president and offer his country our support.

"We need to do all we can to help stabilise the Sahel region, which is also in our own interest," Buhari said.

In his remarks, Sambo congratulated Buhari on the successful return of the abducted schoolboys from Government Science Secondary School, Kankara, in Katsina State, and also his 78th birthday last week.

He pledged that ECOWAS would ensure peaceful and fair elections in Republic of Niger, in spite of current political, legal and security issues, adding that meetings were already being held with stakeholders.