West Africa's regional bloc on Thursday ordered the activation of a standby force for possible use against the junta that took power in Niger in July, saying it wanted a peaceful restoration of democracy but all options including force were on the table.

The threat of an invasion, though not specific, raises tensions in and around Niger, a uranium producer that until the coup was an important ally of the West in the fight against Islamist insurgents devastating the Sahel region.

The junta, which seized power on July 26, had defied an August 6 deadline to stand down set by the Economic Community of West African States (ECOWAS), instead closing Niger's airspace and vowing to defend the country against any foreign attack.

After a summit of its heads of state in the Nigerian capital Abuja, the bloc pledged to enforce sanctions, travel bans and asset freezes on those preventing the return to power of democratically elected President Mohamed Bazoum.

"No option is taken off the table, including the use of force as a last resort," said Nigerian President Bola Tinubu, the ECOWAS chair.

"I hope that through our collective effort we can bring about a peaceful resolution as a roadmap to restoring stability and democracy in Niger," he said. "All is not lost yet."

An official statement was read out which included a resolution asking the bloc's defence chiefs to "activate the ECOWAS Standby Force with all its elements immediately".

Another resolution spoke of ordering "the deployment of the ECOWAS Standby Force to restore constitutional order in the Republic of Niger", immediately followed by another that spoke of restoring such order "through peaceful means".

Reiterating support for the efforts by ECOWAS and a call for the release of President Bazoum, US Secretary of State Antony Blinken said in a statement that the United States would hold the junta accountable for the safety of Bazoum, his family, and detained members of the government.

"The United States appreciates the determination of ECOWAS to explore all options for the peaceful resolution of the crisis," Blinken said.

Security analysts said an ECOWAS force could take weeks or longer to assemble, potentially leaving room for negotiations.

The bloc has planned to create a standby force of thousands of troops for years but was held back by funding delays and insufficient troop commitments, said Ikemesit Effiong, a researcher at SBM Intelligence in Nigeria.

After a string of coups since 2020 and growing militant activity, regional leaders said in December that they were determined to create such a force.

ECOWAS Commission President Omar Alieu Touray told the UN Security Council last month that they were considering two options: a brigade of 5 000 troops at an annual cost of $2.3-billion or the deployment of troops on demand at an annual cost of $360-million.

Thursday's statement did not spell out how the force would be funded, which countries would participate or how many troops and what hardware they could contribute.

"There's probably still a lot that has not been agreed to, such as timeline and red lines and what to do in contingency situations if things continue to go sour," said Aneliese Bernard, director of consultancy Strategic Stabilization Advisors.

'GET THEM OUT'

Speaking to reporters on the sidelines of the summit, Ivory Coast President Alassane Ouattara said he considered the detention of Bazoum "a terrorist act" and promised to supply a battalion of troops to the force.

"We want democracy in our sub-region. We do not accept, we will not accept coups d'etat. These putschists must go. If they don't let Bazoum out to be able to exercise his mandate, I think we should move ahead and get them out," he said, without saying how many troops the country would provide.

ECOWAS sought to project an image of resolution and unity, but the bloc is split, with suspended member states Mali and Burkina Faso, also ruled by military governments, vowing to defend the Niger junta.

"There's still a lot of unknowns, but this (ECOWAS statement) is a significant next step and certainly an escalation of tensions, at least between the regional bloc and the junta bloc that seems to be forming right now, between Mali, Burkina Faso and Niger specifically," said Bernard.

The United Nations and Western powers have backed ECOWAS efforts to persuade the coup leaders to relinquish power and free Bazoum, who is being detained in his residence, but so far they have given no sign they were willing to back down.

Hours before the summit in Abuja, they named a slate of ministers in an apparent move to entrench their position and present themselves as a legitimate government.

Western countries fear Niger could follow Mali's footsteps and seek help from Russia's Wagner Group, which the US has designated a transnational criminal organisation. Wagner's chief, Yevgeny Prigozhin, has welcomed the Niger coup and said his forces were available to restore order.

Despite being one of the world's poorest countries, landlocked Niger, which is more than twice the size of France, is the world's seventh-largest producer of uranium, a crucial material for nuclear power.

Until the coup, it was also an increasingly valuable ally for the West after Mali and others turned against former colonial power France in favour of closer ties with Russia.

US, French, German and Italian troops are stationed in Niger as part of an international struggle against a long-running Islamist insurgency that spread across the Sahel from Mali displacing millions and causing a hunger crisis.

Following a pattern seen after the coups in Mali and Burkina Faso between 2020 and 2022, the junta in Niamey has engaged in vitriolic anti-French rhetoric, seeking to blame France for Niger's problems and accusing it of a range of violations of sovereignty, which Paris has denied.