Jonathan Polin and Rachel Goldberg, parents of Hersh Goldberg-Polin, during a demonstration near Kibbutz Nirim in southern Israel on August 29, 2024
Jonathan Polin and Rachel Goldberg, parents of Hersh Goldberg-Polin, during a demonstration near Kibbutz Nirim in southern Israel on August 29, 2024 AFP

US President Joe Biden said Saturday that the body of Israeli-American hostage Hersh Goldberg-Polin was among six recovered in Gaza by Israeli forces.

"Earlier today, in a tunnel under the city of Rafah, Israeli forces recovered six bodies of hostages held by Hamas," Biden said in a statement.

"We have now confirmed that one of the hostages... was an American citizen, Hersh Goldberg-Polin," the president said, calling his death "as tragic as it is reprehensible."

The 23-year-old was among 251 hostages seized during the October 7 attack on southern Israel by Palestinian militants.

Around 100 hostages remain in captivity, dozens of whom the Israeli military says are dead.

"Make no mistake, Hamas leaders will pay for these crimes," Biden vowed.

"And we will keep working around the clock for a deal to secure the release of the remaining hostages," he added.

The parents of Goldberg-Polin, who was abducted from the Supernova music festival, addressed delegates at the Democratic National Convention in Chicago last month.

Vice President Kamala Harris, the Democratic standard-bearer in the November election, pledged in a statement that Goldberg-Polin's family "are not alone... as they mourn this terrible loss."

"Hamas is an evil terrorist organization," said Harris. "With these murders, Hamas has even more American blood on its hands."

"The threat Hamas poses... must be eliminated and Hamas cannot control Gaza," she said, adding that "the Palestinian people too have suffered under Hamas' rule for nearly two decades."

On Thursday, Goldberg-Polin's parents joined other relatives of hostages rallying near the Gaza border.

"Hersh! It's Mom... I love you, stay strong, survive," Rachel Goldberg-Polin shouted into a microphone.

Her son had hidden in a bomb shelter with other people on October 7 but it was surrounded by gunmen, who attacked it with grenades.

A Hamas video from the day showed him being loaded onto a pick-up truck with a mangled left arm.

He appeared in a proof-of-life video released by Hamas on April 24 in which he said the captives were living "in hell". His left arm had been amputated below the elbow.

Hamas's October 7 attack resulted in the deaths of 1,199 people, mostly civilians, according to an AFP tally based on Israeli official figures.

Israel's retaliatory military campaign has killed at least 40,691 people in Gaza, according to the territory's health ministry. The UN rights office says most of the dead are women and children.