Yaakov Amidror, the former head of Israel's National Security Council, vowed that Israeli forces will ensure the destruction of Hamas and said a ground offensive was needed due to the Palestinian militant group's intricate network of underground tunnels.
Israel will continue to use its air force while preparing a huge ground force operation in the Gaza Strip, Amidror, who is a a retired major general and also a former national security advisor to Prime Minister Benjamin Netanyahu, told CNBC's "Capital Connection" on Friday.
"After the operation, Hamas as an organization will not exist in the Gaza Strip, we will kill as many as possible of its members, and we will destroy every facility of the organization," he said.
"We have to destroy Hamas on the ground to find Hamas members within the underground tunnels, in the holes, in their headquarters," he added.
The United Nations on Thursday condemned Israel's "indiscriminate military attacks against the already exhausted Palestinian people of Gaza" and warned that it could lead to a "severe humanitarian crisis." The organization has also strongly condemned the horrific crimes committed by Hamas, the deliberate and widespread killing and hostage-taking of innocent civilians.
On Friday, Israel told 1.1 million residents in north Gaza to evacuate within 24 hours, according to the U.N., the strongest sign yet that a ground offensive is imminent. Spokesperson of the U.N. Secretary-General Stephane Dujarric said such a move was "impossible."
When asked if the ground operation would come at a cost to Palestinians in the territory, Amidror said Friday that Israeli forces are giving them the time and the ability to move away from a potential battlefield.
Israel's intelligence community believes much of the support and funding the world gave to the people of Gaza to rebuild after previous wars has been taken by Hamas and reinvested in the elaborate system of tunnels and bunkers.
And it's thanks to this labyrinth of tunnels underneath the Gaza Strip, that Israel believes Hamas is still able to fire rockets at Israeli cities, despite Israel's constant air attacks on Gaza. Reports say the rockets are hidden in underground passageways so they can be moved within the tunnel network, frustrating Israel's air force.Â
According to the Israeli Defense Forces, the sophisticated underground system holds electrical generators, intelligence rooms and supplies for Hamas' underground army.
—CNBC's Jason Gewirtz contributed to this report.