United Nations chief Antonio Guterres on Monday defended the UN agency for Palestinian refugees, UNRWA, describing it as a "lifeline of hope and dignity".
During a visit to the Wihdat refugee camp in the Jordanian capital Amman, Guterres said it would be "cruel and incomprehensible" to halt UNRWA's vital services to Palestinian refugees across the region.
His remarks come as the agency faces a financing crisis after several key donor countries cut off funding following Israeli accusations that several UNRWA staff in Gaza were involved in the October 7 Hamas attack.
On Sunday, the chief of the UN agency, Philippe Lazzarini, said that Israel had definitively barred it from making aid deliveries in northern Gaza, where the threat of famine is highest.
The agency employs some 30,000 people across the Palestinian territories, Jordan, Lebanon and Syria, providing healthcare, education and other basic services.
"We must strive to keep the one-of-a-kind services that UNRWA provides flowing because that keeps hope flowing," Guterres said during his visit to the camp.
"In a darkening world, UNRWA is the one ray of light for millions of people. I see that hope here. Now more than ever, we must not take away that hope."
He also sought to "honour the 171 women and men of UNRWA who have been killed in Gaza -- the largest number of deaths of UN staff in our history".
Israel had in January alleged that 12 of the agency's 13,000 employees in Gaza were involved in the October 7 attack on southern Israel.
Multiple governments suspended their contributions to the agency, although several have since resumed payments.
The United Nations has launched both an internal and an independent investigation but has said Israel has not provided it with any evidence to support the claims against its staff.
Hamas's attack resulted in the deaths of 1,160 people, mostly civilians, according to an AFP tally of official Israeli figures.
Israel responded with a relentless military campaign that has so far killed 32,226 people, mostly women and children, according to Gaza's health ministry.