The United States has ordered the partial evacuation of its embassy in Niger following last week's coup.
Hundreds of foreign nationals have already been evacuated from the country, and on Sunday the French embassy was attacked by protesters.
Coup leader Gen Abdourahamane Tchiani has warned against "any interference in the internal affairs" of the country.
Niger is a significant uranium producer and lies on a key migration route to North Africa and the Mediterranean.
US Secretary of State Antony Blinken spoke to the ousted President, Mohamed Bazoum, on Wednesday, the state department says, adding that the US is committed to the restoration of Niger's democratically elected government.
Spokesperson Matthew Miller said that, despite the partial evacuation, the country's embassy in capital Niamey would remain open.
The US is a major donor of humanitarian and security aid to Niger, and has previously warned that the coup could lead to the suspension of all co-operation.
France, the former colonial power in Niger, and the EU have already suspended financial and development aid.
