Israel's war in Gaza will continue throughout 2024, a military spokesman said in a new year's message, insisting that tens of thousands of reservists would be needed for fighting.

"The IDF (Israel Defense Forces) must plan ahead, understanding that we will be required for additional tasks and warfare throughout this year," Daniel Hagari told reporters.

"The objectives of the war require prolonged fighting and we are preparing accordingly."

The war between Israel and the Palestinian militant group Hamas, which rules the Gaza Strip, erupted after Hamas fighters carried out a deadly attack on southern Israel on October 7.

The attack left around 1,140 people dead in Israel, mostly civilians, according to a tally based on Israeli figures.

Some 250 people were also taken hostage by militants. The Israeli army says 129 people still remain in captivity in the Gaza Strip.

Israel's retaliatory land, sea and air assault on Gaza has so far killed at least 21,828 people, most of them women and children, according to the territory's health ministry there.

Hagari said the army was currently planning how to deploy troops in the months ahead.

"Some of the reservists will return to their families and employment this week," he said.

"This will significantly ease the burden on the economy and allow them to gather strength for the upcoming activities in the next year, as the fighting will continue and they will still be required."

Since the ground operation began on October 27 in Gaza, the army has lost 172 soldiers inside the Palestinian territory, including some in friendly fire incidents.