Leaders of Economic Community of West African States have demanded the reinstatement of Ibrahim Boubacar Keita as Malis president.
Keita was forced to resign in the early hours of Wednesday by soldiers who toppled his government on Tuesday.
The ECOWAS leaders made the demand after an emergency summit called to review the situation in Mali.
They also announced plans to visit Bamako, the Malian capital, amid growing concerns about regional stability.
The leaders also called for continued engagement with all parties to the crisis. They mandated former President Goodluck Jonathan, the Special Envoy on the crisis, and ECOWAS Commission President Jean-Claude Kassi Brou, to convey the decisions of the West African leaders to the parties.
The 15-nation bloc convened the virtual Extra-ordinary Session on the socio-political situation in Mali after it suspended it, shut off borders and halted financial flows in response to the overthrow of Keita.
President Muhmmadu Buhari advocated stiffer sanctions on the military regime to force a speedy return to democratic rule.
The President lamented that the situation in Mali is a setback for regional diplomacy, which, according to him, poses a threat to the peace and security of the sub-region.
Buhari, who condemned the Malian military for breaching the very letter and spirit of the ECOWAS protocol on good governance and democracy, urged leaders of the sub-region to ensure that the breach of protocol in Mali does not survive.
Buhari hailed the African Union, the United Nations and other international bodies for condemning the military coup and urged them to work with ECOWAS to restore peace and order in the country by insisting on the supremacy of constitutional provisions.