Mali and Burkina Faso are to send a joint official delegation in a show of solidarity with Niger, which is under the control of the coup leader who toppled the elected government.
"Burkina Faso and Mali are sending a delegation to Niamey," the Malian army said. "The aim: to demonstrate the solidarity of the two countries with the brotherly people of Niger."
The delegation is expected to arrive in Niger on Monday, according to Niger's foreign ministry.
The coup leaders defied a Sunday deadline from the West African bloc ECOWAS to reinstate democratically elected President Mohamed Bazoum or face possible military action.
Mali and Burkina Faso, where the military also took power by force in 2020 and 2022, warned in a joint statement that they would consider military intervention as a declaration of war.