The gathering is taking place on Thursday and Friday in the Ghanaian capital, Accra.

At least 11 of the bloc's 15-member states back a military deployment to reinstate the democratically elected president, Mohamed Bazoum, after diplomatic efforts failed to yield any positive result.

But three Ecowas members currently under military rule themselves - Mali, Burkina Faso and Guinea - support the junta.

Niger's coup leaders have warned they will defend themselves against any intervention.

The discussions in Accra will focus on the resources, the number of troops needed, and a standard operating procedure for combat troops.

Ghana and Nigeria have led previous interventions under the umbrella of the Ecowas Ceasefire Monitory Group, Ecomog, in Liberia and Sierra Leone in the 1990s. The bloc has also intervened in other member countries and more recently in The Gambia.

The meeting comes amid a worsening security situation in Niger. On Tuesday, 17 soldiers were killed and 20 injured in an ambush by Islamist militants.