"The conditions are appalling. There are dead bodies in the corridors. Patients are in a desperate situation,” said Jonathan Whittall, senior humanitarian affairs officer at OCHA in the occupied Palestinian territory.
"This has become a place of death, not a place of healing," he added.
In a video posted on X, Whittall said he along with teams from the World Health Organization (WHO) and the Palestine Red Crescent Society carried out an evacuation mission of the most critical patients that have been trapped inside the hospital.
He added that they tried to reach the hospital for more than a week to provide fuel, water and medical supplies.
Noting that they came there with four ambulances, he said "it is not enough."
"We've been denied consistently. Patients have passed away due to a lack of appropriate care, and we've found critical patients that need to be urgently referred," he said.
The Israeli army raided the medical facility last week after a weeks-long siege, forcing thousands of displaced Palestinians inside the hospital to flee under heavy Israeli bombardment.
According to a local broadcaster, Israeli forces will end their operation at Nasser Hospital soon.
Israel has pounded the Gaza Strip since a cross-border attack by the Palestinian group Hamas in October, in which nearly 1,200 Israelis are believed to have been killed.
The death toll from Israel's offensive on the Gaza Strip has jumped to 29,195, the Palestinian Health Ministry said Tuesday.

Another 69,170 people have been injured so far.

About 85% of Gazans have been displaced by the Israeli onslaught, while all of them are food insecure, according to the UN. Hundreds of thousands of people are living without shelter, and ⁠less than half of the aid trucks are entering the territory than before the start of the conflict.

Israel stands accused of genocide at the International Court of Justice. An interim ruling in January ordered Tel Aviv to stop genocidal acts and take measures to guarantee that humanitarian assistance is provided to civilians in Gaza.