Israeli Foreign Minister Israel Katz has called for Philippe Lazzarini, Commissioner-General of the UN Relief and Works Agency for Palestine Refugees to resign following allegations that some 12 aid workers participated in the October 7 attacks.
A string of countries have paused their funding to the UN aid agency in the wake of Israel's allegations.
The agency says it will not be able to continue operations in Gaza and across the region beyond the end of February if funding is not resumed.
The six-page dossier, seen by Reuters, alleges that some 190 UNRWA employees, including teachers, have doubled as Hamas fighters.
The United Nations has not formally received a copy of the dossier, UN spokesman Stephane Dujarric said on Monday.
The Palestinians have accused Israel of falsifying information to tarnish UNRWA, which says it has fired some staffers and is investigating the allegations.
Palestinian Prime Minister Mohammad Shtayyeh accused Israel of a "premeditated political attack" on the agency, which it has long criticized, and called for restoration of aid funds.
UN Secretary-General Antonio Guterres is due to meet with major UNRWA donors in New York on Tuesday, Dujarric said.
Guterres spoke on Monday with the leaders of Jordan and Egypt and also met with the head of U.N. internal investigations to ensure that an inquiry into the Israeli accusations "will be done swiftly and as efficiently as possible," Dujarric said.
Washington would be looking very hard at the steps UNRWA takes in response to the allegations, US Secretary of State Antony Blinken said at a news conference, describing the allegations as "highly credible" and "deeply, deeply troubling".
Asked under what circumstances and how soon the U.S. could consider resuming support for UNRWA, Blinken said, "It is imperative that UNRWA immediately, as it said it would, investigate, that it hold people accountable as necessary, and that it review its procedures."
More than 26,000 people have been killed in Israel's military campaign against Hamas in Gaza, the enclave's health ministry said. With flows of aid like food and medicine just a trickle of pre-conflict levels, deaths from preventable diseases as well as risk of famine are growing, aid workers say.