Israel is waging a concerted campaign aimed at destroying UNRWA, the head of the UN agency for Palestinian refugees said in an interview published Saturday.
Philippe Lazzarini said calls for his resignation were part of the Israeli government's push.
"Right now we are dealing with an expanded, concerted campaign by Israel aimed at destroying UNRWA," he told the Swiss newspaper group Tamedia.
"It is a long-term political goal because it is believed that if the aid agency is abolished, the status of the Palestinian refugees will be resolved once and for all -- and with it, the right of return. There is a much larger political goal behind this.
"Just look at the number of actions Israel is taking against UNRWA," the main aid body in the Gaza Strip, he said.
He cited measures in the Israeli parliament, moves to remove the agency's VAT exemption and orders for contractors at Israel's port of Ashdod to "stop handling certain food deliveries for UNRWA".
"And all these demands come from the government."
Furthermore, Lazzarini says more than 150 UNRWA installations have been hit since the Gaza war began.
Israel has called for Lazzarini to step down following claims that a Hamas tunnel had been discovered under its evacuated Gaza City headquarters.
Lazzarini said the tunnel was 20 metres below ground and UNRWA as a humanitarian organisation did not have the capabilities to be examining what was underground in Gaza.
He also said there was "no reason" to comply with Israel's lone call for him to quit, "especially since my resignation would not improve the situation at UNRWA".
"The criticisms are not concerned with me personally, but with the organisation as a whole. The calls for resignation are part of the campaign to destroy UNRWA", he said.
The Gaza war began with Hamas' October 7 attack which resulted in the deaths of about 1,160 people in Israel, mostly civilians, according to an AFP tally based on official Israeli figures.
Israel's subsequent assault on Gaza has since killed at least 28,858 people, mostly women and children, according to the Palestinian territory's health ministry.
Several countries -- including the United States, Britain, Germany and Japan -- have suspended funding to UNRWA in response to Israeli allegations that some of its staff participated in the October 7 attack.
Lazzarini said $438 million has been frozen -- the equivalent of more than half of expected income for 2024.
"If all countries continue to withhold their payments, UNRWA's funding will very quickly be at risk," he said.
"From March onwards, expenses exceed income. And without new donors, UNRWA will have to cease operations in April."
He said this applied not only to the Gaza Strip but also to work in the West Bank, Syria, Jordan and Lebanon.
Lazzarini said he was holding meetings with donors and some were "willing to reconsider their decision".
He said the European Commission would pay its contribution of around 82 million euros ($88 million) again from March.
