He is currently being held in detention by the military following a coup last week.

"This is a seizure of power by force. It is not a voluntary departure of the president so there is no reason to talk about this resignation issue," Mr Mahamadou said.

Reflecting on the president’s health, he said:

"President Bazoum is in high spirits. You know, he is a great fighter, he is a seasoned trade unionist and, also, as you know, he is someone who is always outspoken. So, if he is optimistic about the situation, you would better believe it. He really hopes that things will turn out for the best."

In a photograph released overnight, Mr Bazoum was seen for the first time since officers detained him.

Mr Bazoum was pictured meeting Chad's leader, Mahamat Idriss Déby Itno, in Niger's capital, Niamey.

Mr Déby, who also met the coup leaders, is spearheading mediation efforts after West African leaders gave Niger's military seven days to give up power.