The World Health Organization on Friday denied Israel's claim that the WHO was in collusion with Hamas by ignoring Israeli evidence of the "military use" of hospitals in the Gaza Strip.
WHO chief Tedros Adhanom Ghebreyesus also said that such accusations could endanger its staff on the ground.
Tedros was responding to claims made Thursday by Israeli ambassador Meirav Eilon Shahar at a meeting of the UN health agency's board.
"WHO refutes Israel's accusation at the executive board meeting yesterday that WHO is in 'collusion' with Hamas and is 'turning a blind eye' to the suffering of hostages being held in Gaza," Tedros said on X.
"Such false claims are harmful and can endanger our staff who are risking their lives to serve the vulnerable.
"As a United Nations agency, WHO is impartial and is working for the health and well-being of all people."
Earlier this month he told a press conference that healthcare should always be protected. It "cannot be attacked and it cannot be militarised", he said.
Eilon Shahar had said Hamas was embedding itself in hospitals in the Gaza Strip and was using human shields in the Palestinian territory.
In "every single hospital that the IDF searched in Gaza, it found evidence of Hamas' military use," she said Thursday.
"These are undeniable facts that WHO chooses to ignore time and time again. This is not incompetence; it is collusion.
"The WHO knew hostages were held in hospitals and that terrorists operated within.
"Even when presented with concrete evidence of what was happening below ground and above ground ... WHO chooses to turn a blind eye, jeopardising those they are meant to protect."
War erupted on October 7 when Hamas and other militants from Gaza launched unprecedented attacks on Israel which claimed about 1,140 lives, according to an AFP tally of official Israeli figures.
Militants also seized 250 hostages, and Israel says around 132 remain in Gaza. That number includes at least 28 dead hostages, according to an AFP tally based on Israeli figures.
Israel, in response, launched a relentless military offensive that the Palestinian territory's health ministry says has killed at least 26,083 people.
On Thursday, Tedros was moved to tears as he addressed the executive board. The fact that 70 percent of the fatalities in the Gaza Strip have been women and children should be motive enough to bring about a "long overdue" ceasefire, he said.
"If we look for a solution it's always possible," he added, after pausing to compose himself. "It's only the will that's required."
Tedros occasionally becomes emotional when speaking about the impact of war on children, citing his own early years in Ethiopia.
"I am a true believer because of my own experience that war doesn't bring solutions except more war, more hatred, more agony, more destruction," he said Thursday.
"I'm struggling to speak because... the situation is beyond words," he said, wiping his eyes.
