US Secretary of State Antony Blinken called on Saturday for the immediate release of ousted Niger President Mohamed Bazoum and the restoration of democratic order in the country.
Leaders of a coup in Niger declared General Abdourahamane Tiani as head of state on Friday, saying they had ousted Bazoum in the seventh military takeover in West and Central Africa in less than three years.
Bazoum has not made a statement since Thursday morning when he vowed to protect "hard-won" democratic gains in a post on social media.
Blinken told journalists in Brisbane, Australia he had spoken to Bazoum by telephone without providing further details.
The US is calling for his immediate release and restoration of democratic order, Blinken added.
Before the uprising, Niger was seen as the West's most stable ally in an unstable region.
Blinken said a US economic and security partnership with Niger, worth hundreds of millions of dollars, depends on the continuation of the democratic governance and constitutional order, which has been disrupted in the last few days.
"So that assistance is in clear jeopardy as a result of these actions, which is another reason why they need to be immediately reversed," said Blinken, who is meeting with counterparts in Australia.