NIAMEY/ABUJA West African heads of state hold a summit on Thursday aiming to agree on a plan of action for Niger, where coup leaders have refused to stand down despite the bloc's threat that it could use force to restore democracy.

Since the July 26 power grab shocked the region, the defiant junta has rebuffed diplomatic overtures and ignored an Aug. 6 deadline from the Economic Community of West African States (ECOWAS) to reinstate ousted president Mohamed Bazoum.

The meeting in the Nigerian capital, Abuja, could prove a pivotal moment in the standoff. The bloc's leaders are expected to agree on next steps, which could include military intervention - something an ECOWAS official has said would be a last resort.

Envoys of the Nigerian president, and ECOWAS chair, Bola Tinubu met coup leaders in the capital, Niamey, on Wednesday, offering a glimmer of hope for dialogue after previous missions were spurned.

Any escalation would further destabilise West Africa's Sahel region, one of the world' poorest, where a long-running Islamist insurgency has displaced millions and stoked a hunger crisis.

The coup was triggered by internal politics but it has evolved into an international entanglement, with ECOWAS, the United Nations and Western countries putting pressure on the junta to stand down, while military governments in neighbouring Mali and Burkina Faso have vowed to defend it.

(Writing by Alessandra Prentice; editing by Robert Birsel)