The African Union (AU) said it was holding a meeting on Monday on the crisis in Niger following the coup on July 26 that toppled President Mohamed Bazoum.
"AU's Peace & Security Council meets to receive an update on the evolution of the situation in Niger and the efforts to address it," the pan-African body said in a post on X, formerly known as Twitter.
The meeting was taking place at AU headquarters in the Ethiopian capital Addis Ababa, it said.
Those attending include AU Commission chief Moussa Faki Mahamat as well as representatives from Niger and the Economic Community of Western African States (ECOWAS).
Last week, Faki expressed "deep concern" at the reported poor conditions of Bazoum's detention, calling his treatment at the hands of coup leaders "unacceptable."
On Sunday, Niger's military regime vowed to prosecute the democratically elected Bazoum for "high treason" and slammed ECOWAS for imposing sanctions on the country.
Bazoum aged 63 and his family have been held at the president's official Niamey residence since the coup.