The parents of an Israeli-American hostage in Gaza have urged him to "stay strong" and "survive" after Hamas released a proof-of-life video.
Hersh Goldberg-Polin, 23, is seen without his lower left arm in the short clip. It was blown off during Hamas's 7 October attack on southern Israel.
The footage is undated, but he says he has been held for almost 200 days.
In response, his mother and father appealed for more to be done to secure a new hostage release deal.
They urged Israel, Hamas and mediators the US, Egypt and Qatar to "get a deal done" to reunite "all of us with our loved ones and end the suffering in this region".
Speaking under duress in the video posted on Hamas's Telegram account on Wednesday, Mr Goldberg-Polin said he needed medical help and was critical of the Israeli government's attempts to negotiate the hostages' return.
Weeks of indirect negotiations have failed to produce an agreement, with Hamas rejecting the latest proposal for a six-week ceasefire in exchange for the release of 40 of the remaining 133 hostages. At least 30 hostages are presumed dead.
Israel appears to be moving ahead with plans for an offensive in Rafah, southern Gaza, despite warnings of the potentially catastrophic humanitarian consequences for the 1.5 million displaced Palestinians sheltering there.
Hersh Goldberg-Polin was attending the Supernova music festival on 7 October, when Hamas-led gunmen from Gaza stormed Israel's border fence, killing about 1,200 people and seizing 253 hostages, according to Israeli tallies. More than 360 people were killed at the festival.
He sought refuge in a bomb shelter with several dozen others during the attack but gunmen gathered outside and began throwing in grenades.
Before Wednesday, the last time he had been seen alive was in a Hamas video that showed him being loaded on to a pick-up truck, with part of his left arm missing.
In the new video, Mr Goldberg-Polin says he is "fighting for my life with serious wounds all over my body" and that he needs urgent medical attention.
He also accuses the Israeli Prime Minister Benjamin Netanyahu and his government of "abandoning" the remaining hostages and criticises the failure to secure their release.
"Do what's expected of you already and bring us home now," he says.
The Hostages and Missing Families Forum said the Goldberg-Polin family had given permission for the new video of him to be published and used.
"This distressing video serves as an urgent call to take swift and decisive action to resolve this horrific humanitarian crisis and ensure the safe return of our loved ones," it warned.
Hersh Goldberg-Polin's father and mother also released their own video message in response.
"Seeing a video of Hersh today is overwhelming," Jon Polin said. "We're relieved to see him alive but we are also concerned about his health and wellbeing, as well as that of all the other hostages and all of those suffering in this region."
He added: "And we are here today with a plea to all of the leaders of the parties who have been negotiating to date. This includes Qatar, Egypt, the United States, Hamas and Israel.
"Be brave, lean in, seize this moment and get a deal done to reunite all of us with our loved ones and end the suffering in this region."
Rachel Goldberg-Polin then addressed her son directly, saying: "Hersh, if you can hear this, we heard your voice today for the first time in 201 days and if you can hear us, we are telling you: 'We love you, stay strong, survive.'"
In a statement, Israel Defense Forces spokesman Daniel Hagari said: "This psychological terror video is not only a reminder of what Hamas did on 7 October.
"It is a reminder of how sick this terror group is, terrorising the hostages and their families too."
More than 34,200 people have been killed in Gaza since 7 October, according to the territory's Hamas-run health ministry. Israel has been conducting a military campaign to destroy Hamas and free the hostages.
A deal agreed in November saw Hamas release 105 hostages - most of them women and children - in return for a week-long ceasefire and some 240 Palestinian prisoners in Israeli jails.
On Wednesday evening, dozens of people - including friends of Mr Goldberg-Polin - protested outside the prime minister's residence in Jerusalem. Many of them held up signs saying: "Bring them home now."
Police arrested at least two people and used foul-smelling "skunk water" against demonstrators who were blocking streets, according to Israel's Haaretz newspaper.
Police also scuffled with protesters who surrounded the car of far-right National Security Minister Itamar Ben-Gvir outside a synagogue. Mr Ben-Gvir waved to the angry crowd as he was ushered into the vehicle.
A US official told CBS News, the OceanNewsUK's US partner, that the White House had received the video of Mr Goldberg-Polin on Monday and that this was the first time Hamas had publicly released a video of an American hostage.
Jon Polin told Israeli public broadcaster Kan on Thursday morning that Israeli and US officials had told them in a telephone call about the video about an hour before it was posted online by Hamas.
"It seems to us that he is reading something that someone wrote to him," he said. "But the part I'm concentrating on is the last part, which, even if he read it, he spoke straight to me, to my wife Rachel and our daughters Libby and Orly. He told us he missed us and loved us. We take it as truth. Hearing him say that made us stronger."
"We didn't know he was alive - we thought he was, we believed he was, but we didn't know. You take power from the fact that he speaks loud and clear. I think less about what he said and more about how he said it."
