The chief of the UN agency for Palestinian Refugees (UNRWA) decried the situation for UN workers on the ground in Gaza.
He said 64 of his UNRWA colleagues had been killed in just over three weeks, "the highest number of UN aid workers killed in a conflict in such a short time."
Intensifying Israeli military operations in the Gaza Strip have heightened fears of for its 2.4 million inhabitants, where the health ministry said more than 8,300 have been killed, according to AFP.
Despite UN warnings that not enough aid was arriving in Gaza to meet "unprecedented humanitarian needs," Israeli Prime Minister Benjamin Netanyahu said that a ceasefire would amount to surrendering to Hamas, whose gunmen allegedly killed 1,400 people and took more than 230 hostages in an unprecedented attack on 7 October, according to the latest Israeli figures.