The head of Israeli Defense Forces on Thursday admitted to his unit's failure to prevent the Hamas attack and vowed to dismantle the group.

"The IDF is responsible for the security of the country and its citizens, and on Saturday morning in the area surrounding the Gaza Strip, we did not handle it. We will learn, we will investigate, but now is the time for war," Chief of Staff Lt. Gen. Herzi Halevi said in a televised address, his first since Hamas' invasion Saturday.

"It is five days after this murderous, brutal, and surprising incident. The slaughter of our children, our women, our people by Hamas was animalistic and inhumane. The IDF is fighting merciless terrorists who have committed unimaginable acts," Halevi said.

At least 1,200 people have died, and 2,900 others have been injured in Israel since Hamas fired thousands of rockets and an estimated 1,000 fighters crossed into the country from Gaza.

At least 100 Israeli civilians and soldiers have been taken hostage.

Halevi said Israel would attack and dismantle Hamas and Yahya Sinwar, the ruler of the Gaza Strip.

"He and all those under him are dead men walking," Halevi said.

"We will attack them, dismantle them, dismantle their system," he added. "The IDF under my command understands the magnitude of the hour and the magnitude of the task placed on our shoulders. The IDF is responsible for the security of the country and its citizens and on Saturday morning in the Gaza Strip, we failed. We will learn from this, we will face questions about it, but now is the time for war."

He further added, "Gaza will not look the same."

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