Humanitarian chiefs said Thursday they had run out of words to describe the horrors unfolding in Gaza, stressing that states and especially Israel could not "offload" responsibility for the carnage onto aid workers.
There have been growing international warnings after Israel vowed to push ahead with a major operation in southern Gaza's Rafah, where 1.5 million Palestinians remain trapped.
Humanitarians have warned that carrying out aid operations in the area could soon be impossible.
"We are reaching the barriers of language and describing the humanitarian situation," ICRC president Mirjana Spoljaric told a Geneva briefing for diplomats on events in Gaza.
The Red Cross chief told the diplomats their countries were responsible for ensuring the Geneva Conventions are upheld.
"It is not in your interest to offload (that) responsibility... onto humanitarian actors," she said.
"If the way operations are conducted today limit our operational space to a minimum... we will not be able to resolve the problem," she added.
"It doesn't make sense to criticise humanitarian actors for not doing more. You have to enable us to do more."
Christopher Lockyear, head of the medical charity Doctors Without Borders, agreed.
In the current situation, "when we are talking about humanitarian assistance, we're talking about an illusion of aid," he said.
United Nations aid chief Martin Griffiths warned the diplomats not to "look to the humanitarian community as a rescue brigade for the people compressed into that area" in southern Gaza.
"Conditions do not allow it," he said.
"It will not be our fault if people suffer," he insisted. "It will be the fault of those who decide to make this happen."
Hundreds of thousands of displaced Palestinians have been driven into Gaza's southernmost city by Israel's relentless military campaign, seeking shelter in a sprawling makeshift encampment near the Egypt border.
Despite pressure from foreign governments and aid agencies not to invade, Israel insists it must push into Rafah and eliminate Hamas battalions.
Griffiths rejected Israel's suggestion that people could move to safety before the onslaught.
"Evacuation to a safe place in Gaza is an illusion,” he said.
"We must be entirely realistic," he said warning that the possibility that the military operation will spark a panicked "spillover" into Egypt was a "nightmare... that is right before our eyes".
Hamas's attack on October 7 launched the war resulted in the deaths of about 1,160 people in Israel, mostly civilians, according to an AFP tally based on official Israeli figures.
At least 28,663 people, mostly women and children, have been killed in Israel's response, according to the Hamas-run health ministry in Gaza.