France says it will support efforts to overturn Niger's military coup, a day after West Africa's regional bloc said it had a plan for military intervention.
Niger's military takeover, the seventh in West and Central Africa in three years, has rocked the western Sahel region, one of the poorest in the world with strategic significance to global powers.
Defence chiefs from Economic Community of West African States (ECOWAS) have drawn up a plan for military action if the coup leaders do not reinstate elected President Mohamed Bazoum by Sunday, raising the spectre of further conflict in a region that is already battling a deadly Islamist insurgency.
The 59-year-old coup leader, General Abdourahamane Tiani, who received some of his military training in France, said the junta would not back down.
"France supports with firmness and determination the efforts of ECOWAS to defeat this coup attempt," the French foreign ministry said in a statement after Foreign Minister Catherine Colonna met Niger Prime Minister Ouhoumoudou Mahamadou in Paris.
"The future of Niger and the stability of the entire region are at stake."
France, the former colonial power, did not specify whether its backing would entail military support for an ECOWAS intervention in Niger.
ECOWAS has taken a tough stance on the takeover.
Given its uranium and oil riches and pivotal role in the war with the militants, Niger holds importance for the United States, China, Europe and Russia.
The US government has paused foreign assistance programs that benefit the government of Niger but will continue giving humanitarian and food assistance, US Secretary of State Antony Blinken said on Friday.
Under the intervention plan, the decision of when and where to strike will be made by heads of state, said Abdel-Fatau Musah, ECOWAS commissioner for political affairs, peace and security.
He did not give a timeline for intervention or say what the plan would entail.
"All the elements that will go into any eventual intervention have been worked out here, including the resources needed, the how and when we are going deploy the force," he said at the close of a three-day meeting in Nigeria's capital Abuja on Friday.
Whatever option the 15-nation body chooses risks further conflict in a zone where groups linked to Islamic State and al Qaeda thrive on chaos.
They might also face resistance - Niger's neighbours Mali and Burkina Faso, where military juntas have also seized power in recent years, said they would support Niger in the event of military intervention.
Neighbouring Chad, which is not a part of ECOWAS but whose military leader, President Mahamat Idriss Deby, played a role in mediation efforts this week, said it would not intervene militarily.
An ECOWAS delegation was visiting Algeria and Libya on the weekend to drum up support from important regional players ahead of any possible military action.
Nigerian President Bola Tinubu told his government to prepare for options including deployment of military personnel in a letter read out to the Senate on Friday.
Senegal has also said it would send troops.
The Niger junta has cited persistent insecurity as its main justification for seizing power but data on attacks shows security had actually been improving, while violence has soared since juntas took control in Mali and Burkina Faso.
Western donors have cut support to Niger in protest, even though the country relies on aid for 40 per cent of its budget.