There is a narrow opportunity to reverse last week's military takeover in Niger and U.S. diplomatic and military posture there will depend on whether the democratically elected government is reinstated in the coming days and week, a senior U.S. official said on Monday.

The U.S. has condemned the junta's overthrow of elected President Mohamed Bazoum — the seventh military takeover in less than three years in West and Central Africa — which has raised fears for the security of the surrounding Sahel region.

Washington's objective is to support West Africa's regional bloc ECOWAS in its efforts to reverse the takeover, the senior State Department official said, speaking on condition of anonymity.