The healthcare system in Gaza has essentially collapsed, Western doctors who visited the Palestinian enclave in recent months told an event at the United Nations on Monday, speaking of "appalling atrocities" from Israel's offensive.

The four doctors from the United States, United Kingdom and France have been working with teams in Gaza to support its healthcare system, which has been reeling since Israel began its military assault there last October.

The Israeli offensive has displaced nearly 2.3 million people, caused a starvation crisis, flattened most of the enclave, and killed over 31,000 people, according to Gaza's health ministry.

Nick Maynard, a surgeon who was last in Gaza in January with British charity Medical Aid for Palestinians, recalled seeing a child who had been burned so badly that he could see her facial bones.

“We knew there was no chance of her surviving that but there was no morphine to give her," Maynard, a cancer surgeon, told the event at the U.N. headquarters in New York. "So not only was she inevitably going to die but she would die in agony.”

Another seven-year-old child, Hiyam Abu Khdeir, arrived at the Gaza European Hospital with third-degree burns on 40% of her body, after an Israeli airstrike on her home killed her father and brother and injured her mother, said Zaher Sahloul, a critical care specialist with humanitarian group MedGlobal.

After weeks of delay, she was evacuated to Egypt for treatment but died two days later, Sahloul said.

Israel began bombing the Palestinian territory on Oct. 7 in retaliation for Hamas attacks that killed 1,200 people in southern Israel.

International experts have warned that Israel’s assault constitutes a genocide, accusations that the World Court is probing.

Israel denies accusations of genocide and has maintained that it is targeting Hamas, not civilians. It has accused the militant group of using civilians as human shields and says it has a right to defend itself.

The doctors also warned of a large death toll if Israel proceeds with its plan to invade the southern Gazan city of Rafah.

"If there's a grand invasion of Rafah, it will be apocalyptic, the number of deaths we're going to see," said Maynard.

(Reporting by Josie Kao, editing by Deepa Babington)