The general said during an appearance on state television that troops had taken control of the country because of the deteriorating security situation in the Sahel.
Although the general said that Mohamed Bazoum, the chosen president of Niger, had attempted to persuade the populace that "all is well," the bitter truth was "a pile of dead, displaced, humiliation, and frustration."
Despite significant sacrifices, "the security approach today has not brought security to the country," he added.
General Abdou Sidikou Issa, the head of the armed forces, had thrown his support behind the putschists on Thursday, stating it was "to avoid a deadly confrontation."
A coalition of anti-Bazoum parties urged people to demonstrate their support for the putschists' "motivations" on Friday "while disapproving of all change by force".
The putschists have been holding Bazoum since Wednesday morning.
The French presidency said late on Friday that Emmanuel Macron would lead a defense conference on the coup in Niger on Saturday.
Earlier on Friday, as Western powers fought to protect a crucial partner in the insurgency-plagued Sahel, Macron called the coup "dangerous" for the region.
For the people of Niger, for Niger, and for the entire region, this coup is utterly illegal and extremely dangerous, according to Macron.
Bazoum, who is detained at Macron's palace, was reportedly spoken to by Macron, who demanded his reinstatement.
The health of Bazoum was also mentioned by the French president.
The leaders of the putsch who claim to have seized power were not recognized by France, according to a statement from the French foreign ministry on Friday.
The only president of the Republic of Niger is Bazoum, who was "democratically elected by the people of Niger," it said in a statement. "France does not recognize the General (Abdourahamane) Tchiani-led putsch-imposed authorities."