Washington is taking a neutral stance as a key West African bloc threatens to use force on Nigerien coup leaders if they fail to restore constitutional order, the US envoy to the UN said on Tuesday.
Linda Thomas-Greenfield said the US would leave the 15 countries in the Economic Community of West African States to gauge how best respond to the takeover.
“We have not expressed our support for taking any actions by Ecowas,” Ms Thomas-Greenfield told reporters.
"We leave that to Ecowas to decide how that institution, which is part of the region, will react to the situation on the ground."
Ecowas announced travel and economic sanctions against Niger on Sunday, and issued a one-week ultimatum to the junta in Niger to restore constitutional order or risk the possible use of force.
Ms Thomas-Greenfield said Washington supported the efforts of the regional bloc to find a resolution that would enable elected President Mohamed Bazoum to return to leading the African nation.
She is presiding over the UN Security Council for August and said she had personally contacted Mr Bazoum last Thursday, and that he sounded “good”.
“He was under house arrest in his home, with his family,” Ms Thomas-Greenfield said. "He did not sound distressed but I know that the situation he is in is currently quite stressful."
The new junta received support from the military governments of Mali and Burkina Faso, who warned that “any military intervention against Niger will be considered as a declaration of war" against them too.
They said that the “disastrous consequences of a military intervention in Niger … could destabilise the entire region".
Leonardo Santos Simao, UNspecial representative for West Africa and the Sahel, said he hoped that the use of force would “not be necessary” but ultimately it was up to the regional bloc.
Mr Santos Simao is especially concerned that if the situation is not reversed, it is “very likely that the spread of terrorism” in the region will increase.
“But no one wants to see regional conflict happening,” he said.