The announcement complicated last-ditch efforts by international mediators, including the director of the CIA, to broker a cease-fire. Hamas and Qatar, a key mediator, have warned that an invasion of Rafah could derail the talks.
Israel has described Rafah as the last significant Hamas stronghold after seven months of war, and its leaders have repeatedly said they need to carry out a ground invasion to defeat the Islamic militant group.
Lt. Col. Nadav Shoshani, an army spokesman, said some 100,000 people were being ordered to move to a nearby Israel-declared humanitarian zone called Muwasi.