"What Hamas will experience will be difficult and terrible... we are going to change the Middle East," Netanyahu told officials visiting Jerusalem from the country's south, where Hamas militants carried out a surprise attack on Saturday morning.

"This is only the beginning... we are all with you and we will defeat them with force, enormous force."

Hamas militants stormed towns and communities in southern Israel at dawn on Saturday under the cover of a barrage of rocket fire, in the deadliest attack on the country in decades.

Israel has retaliated by carrying out intense air strikes on the Gaza Strip which is controlled by the Islamist group.

More than 700 people have been killed in Israel since Hamas launched its attack on Saturday, while on the Gaza side, at least 560 people have been killed.