Israel's Prime Minister Benjamin Netanyahu announced Wednesday an "emergency government" with an opposition party leader, Benny Gantz, for the duration of the war with Gaza militants.

"Following a meeting... held today, the two agreed on establishing an emergency government and war cabinet," said a joint statement by the premier and Gantz, a former defence minister and army chief.

On social media, Gantz said: "Israel before anything else."

The three-member "war cabinet" would include Netanyahu, Gantz and Defence Minister Yoav Gallant, according to the statement.

It said Gadi Eisenkot, also a former army chief from Gantz's party, and Strategic Affairs Minister Ron Dermer will serve as observers.

Opposition leader Yair Lapid has not joined his former ally Gantz, but the statement said a seat would be "reserved" for him in the war cabinet.

Netanyahu's extreme-right and ultra-Orthodox Jewish allies would remain in government.

Israel's firebrand National Security Minister Itamar Ben-Gvir said on X, formerly Twitter, that he "welcomes the unity, now we must win".

The premier has agreed to freeze the hardline government's divisive judicial overhaul, which had triggered mass street protests - the biggest in the country's history.

"During the war, no bills or government-sponsored motions that are unrelated to the war would be advanced," the statement said.

Gantz last served in a Netanyahu administration in 2020-2021 under a rotation agreement that was meant to see him take the helm for the second half of the government's tenure, but early elections had been called before he was to become prime minister.

Overall, five members of Gantz's National Unity party would become ministers without portfolio, the statement said.

It also noted appointments for senior positions would be automatically extended during the war.

Israeli central bank governor Amir Yaron is due to complete his five-year tenure at the end of the year.