Arab-Israeli Karim Younis, who spent 40 years in prison for killing an Israeli soldier, was released Thursday and greeted by hundreds of supporters in his home village.

With a black and white keffiyeh around his shoulders, 64-year-old Younis was met by a crowd singing the Palestinian national anthem in Ara in northern Israel.

"Every prisoner's story is the story of an entire people and I am proud to be one of those who sacrificed for Palestine," said Younis.

He was convicted in 1983 of the murder three years earlier of an Israeli soldier, Avraham Bromberg, in the occupied Golan Heights. His death sentence was commuted to a 40-year jail term.

"Forty years have passed as if they were nothing, because we consider this to be one of the main pillars of the struggle," said Younis, who was carried through the village while holding a Palestinian flag.

Younis is part of Israel's Arab minority, many of whom identify as Palestinians.

His decades in prison made him the longest-serving Palestinian detainee, either from Israel or the occupied Palestinian territories, according to the Palestinian Prisoners' Club advocacy group.

The organisation said Younis was among a group of prisoners up for release a decade ago as part of a deal mediated by the then-US secretary of state John Kerry, but the negotiations ultimately collapsed.

'Sacrifice'

Younis's brother said his joy was "unlimited" but "incomplete" as their parents died during his sibling's detention.

"His hair and wrinkles have changed, but his resilience increased and multiplied dozens of times," Nadem Younis told AFP.

"His faith in the cause and his knowledge and skill in politics are stronger. Karim has developed through his sacrifices," added the 56-year-old.

Younis was released before dawn Thursday and left by prison authorities at the side of the road in Raanana, a central Israeli city near the prison, the Palestinian Prisoners' Club said.

His cousin, Maher Younis, was also jailed over the soldier's killing and is expected to be freed within weeks.

Israeli Interior Minister Aryeh Deri wrote to the state prosecutor on Tuesday requesting a legal opinion on revoking the citizenship of the two men.

"Stripping their citizenship will be an important message for those who have become symbols for their terrorist acts," Deri wrote.

Karim Younis's lawyer told AFP his client does not hold another nationality.

Israel's national security minister, the extreme-right Itamar Ben-Gvir, called for capital punishment to be carried out for terrorism offences.

"Until we deliver the death penalty to terrorists, I will do everything with God's help so that they get out of prison feeling ashamed," he wrote on Twitter.