Israel-Gaza live updates: Hamas to send a delegation to Cairo for negotiations

A video showing a man who identifies himself as Hersh Goldberg-Polin, a 24-year-old American who was captured at the Nova Music Festival on Oct. 7, and made under duress, was released Wednesday on a Hamas-run Telegram channel.

According to the video, his left arm has been amputated at the forearm. Goldberg-Polin suffered a serious injury to that arm before being captured, his parents told ABC News in an interview in Israel just days after the attack. His family said Wednesday they wanted the video and its message published.

In the heavily edited video made under duress, he denounces Israeli Prime Minister Benjamin Netanyahu for failing to secure the release of the hostages.

It is unclear when the video was filmed. In the video, he makes reference to a holiday and says he has been held for nearly 200 days.

"Hirsch's cry is the cry of all the abductees - their time is up! The State of Israel has no more time to waste, the abductees must be put first, without them the State of Israel will have no resurrection and no victory. All must be brought home - the living for rehabilitation, the murdered for a dignified burial," a spokesperson for the Hostage Release Center said in a statement Wednesday.

This post has been updated.

The World Food Programme warns that famine in the Gaza Strip is getting closer by the day and it could surpass famine thresholds of food insecurity, malnutrition and mortality in six weeks, according to an official.

"We estimate 30% of children below age of two is now acutely malnourished or wasted, and 70% of the population in the north is facing catastrophic hunger. There is reasonable evidence that all three famine thresholds -- food insecurity, malnutrition, mortality -- will be passed in the next six weeks," said Gian Carlo Cirri, the director of the World Food Programme's Geneva office.

"The conflict makes it so difficult and sometimes impossible to reach affected people that as humanitarians we usually don't -- for humanitarian principles, to abide to those principles -- we don't call for ceasefire. On these two contexts, we have no other choice than asking for a ceasefire. This is the only way for us as humanitarians, as World Food Programme, to access these people that are in acute needs."

-ABC News' Will Gretsky

More than 310 aid trucks entered Gaza Tuesday, the highest number of aid vehicles that have entered Gaza since the Israel-Hamas conflict began, according to the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA).

"It needs now to be sustained & further increased," the agency said in a statement.

The UNRWA, which has been critical of the aid effort in Gaza, reiterated its calls for increased access for humanitarian groups to prevent famine in the region.

-ABC News' Will Gretsky

Israel has dramatically increased the flow of humanitarian supplies into Gaza, allowing on average 200 aid trucks a day, with some days as many as 400 trucks getting through, according to a top U.S. official.

Now, the focus needs to move beyond "counting trucks" and instead look to ensure the right supplies are being distributed throughout Gaza, according to David Satterfield, the State Department’s special envoy for Middle East humanitarian issues.

"Our first priority was -- because it had to be -- averting famine," Satterfield told reporters on Tuesday. "But we now need to move on beyond that goal to addressing the true needs: sanitation, availability of medicines, availability of potable water, the specialized care required for these vulnerable populations."

The United Nations this week is conducting a more detailed assessment on the needs for the civilian population, Satterfield said.

He said the U.N. needs more trucks that are cleared by the Israeli military to operate inside Gaza. He also said the Erez crossing between Gaza and Israel and an additional northern crossing must become accessible.

"Our work is focused every day, every hour, on seeing continuous progress made," he said.

-ABC News’ Anne Flaherty