“The only path is a diplomatic one,” Italian Foreign Minister Antonio Tajani told La Stampa newspaper.
“I hope that the ultimatum of the Economic Community of West African States (ECOWAS), which expired last night at midnight, will be extended today,” he added.
“A solution must be found. It’s not set that there is no way other than war.”
Germany’s foreign ministry echoed the calls for a diplomatic solution.
“We support ECOWAS in its mediation efforts, which are still ongoing,” a ministry spokesman told a press briefing.
The expiry of the bloc’s deadline did not mean there would automatically be military action, he added.
“We hope that these (mediation) efforts will ultimately lead to success and that constitutional order will be restored in Niger.”
Bazoum was overthrown on July 26 when members of his own guard detained him at the presidency.
ECOWAS issued its ultimatum a week ago, demanding the generals relinquish power by midnight Sunday (2300 GMT).