The West African bloc ECOWAS stands ready to intervene militarily in Niger should diplomatic efforts to reverse a coup there fail, a senior official told army chiefs who were meeting in Ghana on Thursday to discuss the details of a standby force.

Niger military officers deposed President Mohamed Bazoum on July 26 and have defied calls from the United Nations, ECOWAS and other countries to reinstate him, prompting West African heads of state to order the standby force to be assembled.

"Let no one be in doubt that if everything else fails, the valiant forces of West Africa are ready to answer to the call of duty," ECOWAS Commissioner for Political Affairs, Peace and Security Abdel-Fatau Musah said.

"By all means available, constitutional order will be restored in the country," he told assembled defense chiefs from member countries, listing past ECOWAS deployments in Gambia, Liberia and elsewhere as examples of readiness.

Niger has strategic importance beyond West Africa because of its role as a hub for foreign troops involved in the fight against Islamist insurgents in the Sahel region and its uranium and oil reserves.

In Niger's capital Niamey, where large crowds have taken part in protests against ECOWAS and in favor of the coup leaders, residents rejected the idea of an outside intervention to reinstate the elected president and civilian government.

'Cat and mouse'

Musah accused the Niger coup leaders of "playing cat-and-mouse" with ECOWAS by refusing to meet with its envoys and seeking justifications for their takeover of power.

He said most of the bloc's 15 member states were prepared to participate in the standby force that could intervene in Niger. The exceptions were those also under military rule – Mali, Burkina Faso and Guinea – and tiny Cape Verde.

Musah criticized the junta's announcement that it had elements to put Bazoum, who is being detained, on trial for treason. The United Nations, European Union and ECOWAS have all expressed concerns over the conditions of his detention.

"The irony of it is that somebody who is in a hostage situation himself is being charged with treason. When did he commit that high treason is everybody's guess," Musah said.

(With input from Reuters)