Niger President Mohamed Bazoum is being held in the presidential palace by soldiers.
France has warned coup plotters in Niger Republic to retrace their steps.
Reacting to the Coup on Friday, France said that a power grab in Niger was not definitive and that those responsible still had time to accede to international demands that the ousted president be reinstated.
Niger President Mohamed Bazoum is being held in the presidential palace and it remains unclear who is in charge of the country after soldiers on Wednesday evening declared a coup that sparked widespread condemnation.
In a statement signed by its chief of staff, the army on Thursday declared support for the soldiers who stripped President Mohamed Bazoum of power. It said its priority was to avoid destabilising the country.
Speaking to reporters on the sidelines of the trip by French President Emmanuel Macron to Papua New Guinea, France's foreign minister
Catherine Colonna said countries in the West African ECOWAS bloc were likely to meet on Sunday with a discussion on imposing sanctions on Niger.
France colonized Niger until the country gained independence in 1960. France and the US are two Western countries with great military presence and military bases in Niger but there are reports that Russia has been planning to stake its footprints in the country's military and political landscape.
On Thursday, citizens could be seen burning buildings belonging to the ruling party with some people carrying Russian flags and pro-Russian slogans.
"If you hear me say attempted coup d'etat, it's because we don't consider that things are definitive," Colonna was quoted by French media as saying.
Colonna said Macron had spoken to Bazoum on Friday and that he was in good health and should be released as a condition of restoring constitutional order.
"President Bazoum must be restored to his constitutional functions," Colonna said.
A French diplomatic source said on Thursday that the situation remained "very confused".