UNITED NATIONS -- Philippe Lazzarini, Commissioner-General of the UN Relief and Works Agency (UNRWA) for Palestine Refugees in the Near East, warned Monday against attempts to dismantle the agency.

Lazzarini expressed concerns at the UN General Assembly about "a deliberate and concerted campaign" aiming to cease the agency's activities, amidst accusations from Israel of the agency harboring over 450 "military operatives" from Hamas and other groups.

"UNRWA is facing a deliberate and concerted campaign to undermine its operations, and ultimately end them," Lazzarini said.

UNRWA, critical for humanitarian aid in Gaza, is "functioning hand-to-mouth" after a significant funding halt, triggered by Israel's accusations against 12 UNRWA staff members of being involved in a Hamas attack, said the UNRWA head.

Lazzarini warned media the same day that the "worst is yet to come" for UNRWA and its beneficiaries.

"We are in a situation where there is a political decision to eliminate UNRWA," he said, citing Israeli Prime Minister Benjamin Netanyahu's announcement that there is "no place" for UNRWA in Gaza as well as attempts to block and evict the UNRWA staff from its premises "with the aim to dismantle the agency."

He confirmed that a yet-to-be-published UNRWA report will document the experiences of those released from Israeli detention since October last year, including UNRWA staff members, who "have been traumatized" by their "ordeal."

"It's a very broad range of ill-treatment, and we heard stories of people being systematically humiliated, obliged to be naked, subjected to verbal and psychological abuse," he said, providing a snapshot of the report's findings.