(AFP) - Leaders from West African bloc ECOWAS will meet on Thursday for an emergency summit on the coup in Niger, after the country's military chiefs defied an ultimatum to restore the elected president.

Two weeks after the coup that toppled Mohamed Bazoum, the Economic Community of West African States (ECOWAS) says it is seeking a diplomatic solution but has not ruled out using force to resolve the crisis.

Important decisions are expected from the gathering in Nigeria's capital Abuja, according to a statement from the 15-nation organisation on Tuesday.

Struggling to stem a cascade of coups among its members since 2020, the bloc gave the troops who seized power on July 26 until last Sunday to reinstate Bazoum or face the potential use of force.

But the coup leaders remained defiant and the deadline passed without action.

In their latest show of resistance against international pressure, the military leaders named a new government, according to a decree read out on national television on Thursday.

Prime Minister Ali Mahaman Lamine Zeine will lead the 21-member administration, with generals from the new military governing council heading the defence and interior ministries.

The possibility of a military intervention in Niger, a fragile nation that ranks among the world's poorest, has sparked debate within ECOWAS and warnings from neighbouring Algeria and Russia.

Niger's neighbours Mali and Burkina Faso, both ruled by military governments who seized power in coups, have said an intervention would be tantamount to a declaration of war on their countries.

- Hopes for 'real discussions' -

On Tuesday, a bid to send a joint team of ECOWAS, UN and African Union representatives to the capital Niamey was rejected by the coup leaders.

The nomination of a new prime minister by the coup leaders earlier this week appeared to signal the start of a transition to a new government.

But in a twist on Wednesday, a former emir of the Nigerian city of Kano revealed that he had met with the coup leaders to help mediate the crisis.

Sanusi Lamido Sanusi told Nigerian state television he had spoken to coup leader General Abdourahamane Tiani and would deliver a "message" to Nigeria's President Bola Tinubu, though he was not an official government emissary.

"We came hoping that our arrival will pave the way for real discussions between the leaders of Niger and those of Nigeria," said Sanusi, who is known to be a close friend of Tinubu.

Current ECOWAS chair Nigeria is taking a hard line against last month's coup, the fifth in Niger since independence from France in 1960.

Speaking before flying to Abuja on Wednesday, Guinea-Bissau's President Umaro Sissoco Embalo said the future of ECOWAS was at stake following coups in four member states, namely Mali, Guinea, Burkina Faso and Niger.

Bazoum remained Niger's sole recognised president and coups must be banned, he added.

- 'Deplorable living conditions' -

The leader of the United Nations added to a chorus of concern about the welfare of 63-year-old Bazoum, who has been detained by members of his presidential guard since July 26.

Antonio Guterres denounced "the deplorable living conditions that President Bazoum and his family are reported to be living under", according to a UN statement.

CNN reported Wednesday that Bazoum was being kept in isolation and forced to eat dry rice and pasta.

Countries in the fragile Sahel region are battling a jihadist insurgency that erupted in northern Mali in 2012, spread to Niger and Burkina Faso in 2015, and is now causing jitters in states on the Gulf of Guinea.

The bloody campaign has been devastating for those three countries, which have turbulent histories and are among the poorest nations in the world.

Bazoum's election in 2021 had helped Niger cement close ties with France and the United States, which have major bases and troop deployments in the country.

France last year withdrew its forces from Mali and Burkina Faso after falling out with their military leaders, refocussing its anti-jihadist strategy on Niger.

© Agence France-Presse