Speaking ahead of an ECOWAS crisis summit on Niger on Sunday, the junta said: "The aim of this meeting is to approve a plan of aggression against Niger, in the form of an imminent military intervention in Niamey, in cooperation with African countries who are not members of the regional body and certain Western nations."

The statement was read out on national television on Saturday evening by Amadou Abdramane, a member of the junta which this week ousted elected president Mohamed Bazoum and declared itself in charge.

West African leaders were scheduled to meet on Sunday in the capital of Nigeria, Abuja, to discuss the military takeover in Niger, the latest coup to affect the unstable Sahel region.

The 15-nation Economic Community of West African States (ECOWAS), of which Niger is a member, could consider imposing sanctions on the junta.

Former colonial ruler France and the European Union have already suspended security cooperation and financial aid to Niger.

Last year, ECOWAS leaders agreed to create a regional security force to intervene against jihadists and prevent military coups.

Details on how that force would work and its funding are still unclear, with ECOWAS defence ministers expected to make decisions later this year.