Israel has said UNRWA, which has helped Palestinians for more than 70 years, is not fit for purpose and major donors have suspended funding after allegations that 12 of UNRWA's thousands of Palestinian employees were suspected of involvement in the Oct. 7 Hamas attack on Israel that started the Gaza war.

"We will hit a negative cashflow as from March and then it will be accelerated in April unless this frozen contribution is unlocked," UNRWA head Philippe Lazzarini told Irish national broadcaster RTE before a meeting in Dublin with the foreign minister.

Negative cashflow is when an organisation has more money outgoing than incoming, impacting its ability to sustain itself.

Lazzarini has held extensive consultations with donors, including a trip to Gulf countries and Brussels, in recent days to try to plug UNRWA's funding shortfall of some $440 million.

Some UNRWA donors, such as the United States and Britain, have indicated they will not resume support until the U.N.'s internal investigation into the allegations ends. A preliminary report is due to be published in the next several weeks.

"If we don't get (the funding), we will be in trouble and our ability to operate will be compromised," Lazzarini told RTE, calling on the donors to review their decision.

Lazzarini said earlier this week that calls for UNRWA to be dismantled were short-sighted and terminating its mandate would deepen the humanitarian crisis in Gaza.