He spoke on Saturday evening, after an ECOWAS delegation met both Tiani and toppled President Mohamed Bazoum in the capital Niamey earlier that day, Reuters reported.
ECOWAS Commissioner Abdel-Fatau Musah told Reuters on Monday that the bloc's position remained clear.
"Release Bazoum without preconditions, restore constitutional order without further delay," he said via WhatsApp in response to a query about the proposed elections delay.