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 Israel was alone in calling for him to quit and there was "no reason" to comply with a single UN member state's demand for him to go, "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.
Israel has killed more than 28,800 people since it began its unprecedented air and ground assault on Gaza on October 7, following the surprise attack by Hamas in southern Israel which left about 1,160 dead.
Hamas took more than 250 people hostage, around 130 of whom are still in Gaza - including 30 who are presumed dead from Israeli airstrikes.