The operation will expand the existing 500m buffer zone created last November to a full kilometre, a move meant to halt the passage of weapons and militants.
The officials, speaking on condition of anonymity because they were not authorised to speak to journalists, expect to complete the expansion by the middle of next week.
The forced evictions are displacing a population with longstanding grievances against the government of Egypt's President Abdel-Fattah el-Sissi.
