Israel's president Reuven Rivlin tasked ex-military chief Benny Gantz on Wednesday with forming a new governing coalition and bringing Israel out of the longest political impasse in its history.

Gantz is the first politician other than Prime Minister Benjamin Netanyahu to receive such a mandate since 2009.

Following deadlocked elections on September 17, Netanyahu had tried to form a coalition, but finally gave up on Monday - his second such failure this year.

At a press conference in Jerusalem, Rivlin called on political parties to make "concessions", while Gantz promised to "try to form a liberal union government".

He is expected to face difficulties in forming a majority coalition, despite expressing confidence he can reach a deal for a unity government.

He will have 28 days to try and if he too fails, Rivlin can ask parliament to agree on another candidate for prime minister.

If that also fails to produce a new government, Israel could face yet another election - its third in the space of a year.

"We must behave responsibly towards Israeli citizens and avoid new elections," Gantz said Wednesday, adding that there would be room for "all elements of Israeli society" in his coalition. Gantz presents himself as a leader who can heal Israel's divisions, which he says Netanyahu has exacerbated.

A 60-year-old former paratrooper, Gantz had no previous political experience when he declared himself Netanyahu's electoral rival in December.

He was born on June 9, 1959, in Kfar Ahim, a southern Israeli village that his immigrant parents, both Holocaust survivors, helped to establish.

Copyright Agence France-Presse, 2019