Niger's new junta on Monday accused former colonial ruler France of wanting to "intervene militarily" to reinstate deposed President Mohamed Bazoum.
"In its search for ways and means to intervene militarily in Niger, France with the complicity of some Nigeriens, held a meeting with the chief of staff of the Nigerien national guard to obtain the necessary political and military authorisation needed," said a statement read out on national television.
In another statement, the putschists accused the security services of an unnamed Western embassy of firing teargas Sunday on pro-coup demonstrators in the capital Niamey.
It said six people had been hospitalised after the incident.
French President Emmanuel Macron had Sunday vowed "immediate" action if French citizens or interests were attacked in Niger, after thousands of Nigeriens rallied outside the French embassy.
Anti-French sentiment runs high in some former African colonies as the continent becomes a renewed diplomatic battleground, with Russian and Chinese influence growing.
France has some 1,500 troops in the West African nation, which is one of its last allies in the Sahel region, after French forces had to withdraw from neighbouring Mali earlier this year.
Following Mali and Burkina Faso, Niger has become the third country in the Sahel to be undermined by jihadist attacks linked to the Islamic State group and Al-Qaeda.