West African leaders will discuss Niger on Thursday after the junta that seized power there on July 26 defied a deadline to reinstate the ousted president or face the threat of military intervention, the regional bloc said on Monday.

The Economic Community of West African States (Ecowas), which has sent military forces into troubled member states in the past, had told the junta to stand down by Sunday, but coup leaders instead closed Niger’s airspace and pledged to defend the country.

“Niger’s armed forces and all our defence and security forces, backed by the unfailing support of our people, are ready to defend the integrity of our territory,” a junta representative said in a statement on national television.

Coup leaders also called on young Nigeriens to be ready to serve their country in its time of need – a rallying call that several students at the capital’s Abdou Moumouni university said on Monday they would heed.

“No sacrifice is too much … for our country, we are ready to give our lives,” said economics masters student Soumaila Hamadou on the rain-drenched campus.

Ecowas said it would hold an extraordinary summit to discuss the Niger crisis on Thursday in Abuja, the Nigerian capital where it has its headquarters, but its statement made no direct reference to the missed deadline.

Niger’s capital Niamey appeared calm on Monday with people going about their business as usual, but the closure of Nigerien airspace has already disrupted the skies.

Landlocked Niger is more than twice the size of France and many flight paths across Africa would normally pass above it. Air France suspended flights to and from Ouagadougou in Burkina Faso and Bamako in Mali, which both border Niger, until August 11 and warned that some flight times would increase.

Ecowas has taken a harder stance on the Niger coup, the region’s seventh in three years, than it did on previous ones. The credibility of the 15-nation club is at stake because it had said it would tolerate no further such overthrows.

Ecowas defence chiefs agreed on Friday on a possible military action plan if the detained president, Mohamed Bazoum, was not released and reinstated, although they said operational decisions would be decided by heads of states.

But the bloc’s unity has been broken by a promise from the ruling juntas in Mali and Burkina Faso, both member states, to come to Niger’s defence if needed.

Both countries were sending delegations to Niamey to show solidarity, the Malian army said on social media on Monday, and flight tracking website FlightRadar24 showed a Burkina Faso military plane arriving in Niamey at around 1120 GMT.

A fracture within Ecowas and escalation of the stand-off with Niger would further destabilise one of the world’s poorest regions, already facing a hunger crisis and an Islamist insurgency that has killed thousands and displaced millions.

Niger’s uranium and oil reserves and its pivotal role in a war with Islamist militants in the Sahel region give it economic and strategic importance for the United States, Europe, China and Russia.

African and Western allies have imposed sanctions and cut aid to Niger in attempts to pressure the junta to step down. Germany said on Monday that sanctions were on the table and described the junta’s flight ban as a setback.

Italian Foreign Minister Antonio Tajani, however, said in an interview published on Monday that Ecowas should extend its deadline for the reinstatement of Bazoum.

“The only way is the diplomatic one,” Tajani told La Stampa newspaper.

“It is right that he [Bazoum] should be freed, but we cannot do it. The United States are very cautious about this, it is unthinkable that they would start a military intervention in Niger,” Tajani added.

The junta appears to enjoy support from at least part of the population. At pro-coup rallies in Niamey, some participants have cast the situation as a patriotic battle by the former French colony to retain its independence in the face of imperialist interference. Some have held up Russian flags and expressed anti-French sentiment.

France warned its citizens against all travel to Niger, while the Chinese Embassy in Niamey said its nationals in Niger should leave for a third country or return home if they had no reason to stay.

US Secretary of State Antony Blinken on Friday called for “the immediate restoration of Niger’s democratically elected government”, and said the US would pause certain foreign assistance programmes that benefit the government of Niger.

“There is a rather extraordinary alignment of the West, and of Africa… to condemn what is happening,” French European Affairs Minister Laurence Boone said on Monday.

“I hope that we will be able to restore democracy and the constitution without blood and in peace,” she said on French television channel LCI.