The US and UN are concerned about the health and safety of Niger’s elected President, Mohamed Bazoum, who has spent more than two weeks under house arrest.
“We are greatly worried about his health and his personal safety and the personal safety of his family,” a US state department spokesman said.
The Economic Community of West African States (Ecowas) had given Niger’s coup leaders until Sunday to stand down.
Ecowas said on Thursday it was still considering all options.
“No option is taken off the table, including the use of force as a last resort,” Nigeria’s President, Bola Tinubu, who chaired a meeting of Ecowas leaders, said.
“We remain steadfast in our commitment to supporting Niger in the journey towards peaceful democratic stability,” he added.
Ahead of the meeting, Muslim clerics from northern Nigeria, which shares a long border with Niger, had urged President Tinubu against using force to oust the coup leaders.
UN Secretary General, Antonio Guterres, said he was concerned about the reportedly “deplorable living conditions” Mr Bazoum and his family were in.
Earlier, his party said they were being detained under “cruel” and “inhumane” conditions, Reuters news agency reported.
Mr Bazoum was deposed on 26 July.
Since then, a military junta has ruled Niger while Mr Bazoum has been kept in the presidential palace. Members of the junta have made no comment about the ousted leader’s condition.
On Tuesday, US Secretary of State, Antony Blinken, called Mr Bazoum and assured him of the US’s ongoing support, Washington said.
US State Department spokesman, Matthew Miller, added: “As time goes on, as he’s held in isolation, it’s a situation that is of growing concern to us.”
Mr Bazoum’s political party, PNDS-Tarayya, claimed in a statement that Mr Bazoum and his family had no access to running water, electricity, fresh goods or doctors.
The statement echoed previous comments made by Niger’s elected prime minister, Ouhoumoudou Mahamadou, who has said Mr Bazoum was being held with his wife and son without electricity or water.