The Economic Community of West African States (ECOWAS) canceled a crisis meeting about Niger that was scheduled for Saturday, as the bloc's parliament said it would send a delegation to meet coup leaders in the country.
The regional bloc had approved a military force to reinstate elected President Mohamed Bazoum, who was ousted by members of his guard on July 26.
Chiefs of staff from member states of the West African bloc were scheduled to attend a meeting on Saturday in the Ghanaian capital Accra but later indefinitely suspended it for "technical reasons."
Sources said the meeting was originally set up to inform the organization's leaders about "the best options" for activating and deploying the standby force.
"The military option seriously envisaged by ECOWAS is not a war against Niger and its people but a police operation against hostage takers and their accomplices," Niger's Foreign Minister Hassoumi Massaoudou said Saturday.
ECOWAS is determined to stop the sixth military takeover in the region in just three years and has severed financial transactions and electricity supplies and closed borders with landlocked Niger, blocking much-needed imports to one of the world's poorest countries.
Thousands of coup supporters rallied in the Niger capital Niamey on Friday to protest against the ECOWAS plan to send troops.
'Down with ECOWAS'
Protesters gathered near a French military base on the outskirts of Niamey shouting "Down with France, down with ECOWAS."
Niger's new leaders have accused former colonial power France, a close Bazoum ally, of being behind the hardline ECOWAS stance.
Many protesters brandished Russian and Niger flags and shouted their support for the country's new strongman, General Abdourahamane Tiani.
"We are going to make the French leave! ECOWAS isn't independent, it's being manipulated by France," said one demonstrator, Aziz Rabeh Ali.
France has around 1,500 troops in Niger.
It is facing growing hostility across the Sahel, withdrawing its forces from neighboring Mali and Burkina Faso last year.
Niger's new leaders scrapped defense agreements with France last week, while a hostile protest outside the French embassy in Niamey on July 30 prompted Paris to evacuate its citizens.
Fears for Bazoum
The European Union and the African Union joined others in sounding the alarm for Bazoum on Friday, while on Saturday his entourage said he was able to see a physician.
Bazoum "had a visit by his doctor today," a member of his entourage told AFP, adding the physician had also brought food for Bazoum, his wife and his son. "He's fine, given the situation," the source added.
U.N. rights chief Volker Turk said Bazoum's reported detention conditions "could amount to inhuman and degrading treatment, in violation of international human rights law."
German Foreign Minister Annalena Baerbock warned that the "coup plotters must face harsh consequences should anything happen" to Bazoum or his family.
Top U.S. diplomat Antony Blinken said he was "dismayed" by the military's refusal to release Bazoum's family as a "demonstration of goodwill."
A source close to Bazoum said: "He's OK, but the conditions are very difficult." The coup leaders had threatened to assault him in the event of military intervention.
Human Rights Watch said it had spoken to Bazoum earlier this week. The 63-year-old described the treatment of himself, his wife and their 20-year-old son as "inhuman and cruel," HRW said.
"I'm not allowed to receive my family members (or), my friends who have been bringing food and other supplies to us," the group quoted him as saying.
"My son is sick, has a serious heart condition, and needs to see a doctor," he was quoted as saying. "They've refused to let him get medical treatment."
Under pressure to stem a cascade of coups among its members, ECOWAS had previously issued a seven-day ultimatum to the coup leaders to return Bazoum to power.
But the generals defied the deadline, which expired on Sunday without any action being taken.
The coup leaders have since named a new government, which met for the first time on Friday.
Nigeria religious chiefs in Niamey to meet Niger military leaders
Meanwhile, Nigerian religious leaders arrived in Niger on Saturday to meet members of the military who seized power last month, a source close to the regime told AFP.
Newly appointed Prime Minister Ali Mahaman Lamine Zeine received the delegation in the capital Niamey.