U.S. defense officials say they are cautious and aware of Niger’s recent announcement which revoked a military accord that allowed personnel from Washington’s Department of Defense to operate in the West African nation. In an interview with the host of VOA's Africa 54, Esther Githui-Ewart, U.S. National Security Correspondent Jeff Seldin said Washington has not yet received a deadline from Niger on when troops should vacate the nation. "There is optimism that through continued talks the U.S.-Niger military relationship, specifically to counter terrorism, can in some way continue and that perhaps they can have an arrangement where we can use this critical base," Seldin added.