The Israeli military said on Monday the chief of its intelligence directorate has resigned after taking responsibility for failures leading to the unprecedented October 7 attack by Hamas.

Major General Aharon Haliva is the first high-ranking official to step down for failing to prevent the attack that shocked Israel and the international community.

"Major General Aharon Haliva, in coordination with the chief of the general staff, has requested to end his position, following his leadership responsibility as the head of the intelligence directorate for the events of October 7," the military said in a statement.

"It was decided that MG Aharon Haliva will end his position and retire from the IDF (army), once his successor is appointed in an orderly and professional process."

In his resignation letter, Haliva, who served in the force for 38 years, took responsibility for failing to prevent the attack.

"On Saturday, October 7th 2023, Hamas committed a deadly surprise attack against the state of Israel," he wrote in the letter, a copy of which was given to journalists by the military.

"The intelligence division under my command did not live up to the task we were entrusted with.

"I carry that black day with me ever since. Day after day, night after night. I will forever carry with me the terrible pain of the war."

In his letter, Haliva called for a "thorough investigation into factors and circumstances" that led to the attack.

The Hamas attack resulted in the deaths of 1,170 people, mostly civilians, according to a tally based on official Israeli figures.

Since then, Israel has vowed to eliminate Hamas and is engaged in a blistering assault against the militant group which rules the Gaza Strip.

The Palestinian territory's health ministry said 34,097 people have been killed in Israel's military campaign in Gaza, most of them women and children. (AFP)