UNITED NATIONS (AP) -- The United Nations stressed Tuesday that if Israel puts in place new laws cutting ties with the U.N. agency for Palestinian refugees, the Israeli government will have to meet their needs under international law.

Secretary-General Antonio Guterres says there is no other U.N. alternative to the agency, known as UNRWA. It has been a lifeline during the Israel-Hamas war in Gaza, and the Israeli legislation "will have a devastating impact on the humanitarian situation" in the Palestinian territories, U.N. spokesman Stephane Dujarric said.

The U.N. agencies for children, health and migration also stressed that UNRWA is the "backbone" of the world body's operations in Gaza, where people rely on emergency food aid during the more than yearlong war, which has killed tens of thousands and left much of the enclave in ruins.

The United Nations is heartened by statements of support for UNRWA from all quarters and countries, Dujarric said, and "we would very much appreciate efforts by any member state to help us get over this hurdle."

Israel has alleged that some of UNRWA's 13,000 staff members in Gaza participated in the Oct. 7, 2023, attacks by Hamas, which sparked the war in Gaza. It also has accused hundreds of UNRWA staff of having militant ties and said it has found Hamas military assets in or under the agency's facilities.

Israel's new laws

Two laws passed Monday could prevent UNRWA from continuing its work. Even the United States, Israel's closest ally, joined many governments and humanitarian organizations in opposing the legislation, which doesn't take effect for three months.

Guterres sent a letter Tuesday to Israeli Prime Minister Benjamin Netanyahu outlining his concerns and "the issues of international law that have been raised," Dujarric said.

As an occupying power, under international humanitarian law, Israel is required to ensure the needs of the Palestinians are met, including for food, health care and education, the U.N. spokesman said. And if Israel isn't in a position to meet those needs, "it has an obligation to allow and to facilitate the activities of the U.N., including UNRWA and other humanitarian agencies, to meet those needs," he said.

"Should UNRWA cease to operate -- and for us there is no alternative -- Israel would have to fill the vacuum," Dujarric said. "Otherwise, it would be in violation of international law."

Israel's U.N. Ambassador Danny Danon responded to the secretary-general's letter to Netanyahu by saying, "Rather than condemning UNRWA for turning a blind eye to terrorism and in some cases participating in terrorism, the U.N. instead condemns Israel."

He claimed in a statement that UNRWA isn't interested in providing humanitarian aid to Gaza, calling it "nothing but an arm of Hamas operating under the guise of the United Nations."

"Israel will continue to facilitate humanitarian aid in Gaza according to international law," Danon said, "but UNRWA has failed in its mandate and is no longer the right agency for this job."

Dismay from U.N. agencies

World Health Organization spokesman Tarik Jasarevic said UNRWA health workers have provided over 6 million medical consultations over the past year. They also have offered immunizations, disease surveillance and screening for malnutrition, and UNRWA's work "couldn't be matched by any agency -- including WHO," he said.

Jeremy Laurence, spokesman for the U.N. human rights office, said that "without UNRWA, the delivery of food, shelter, health care, education, amongst other things, to most of Gaza's population would grind to a halt."

UNRWA was established by the U.N. General Assembly in 1949 to provide relief for Palestinians who fled or were expelled from their homes before and during the 1948 Arab-Israeli war that followed Israel's establishment, as well as their descendants.

Israel faces criticism

Timed to the Israeli laws passing, Norway announced Tuesday that it will ask the 193-nation General Assembly to request a ruling from the top United Nations court about whether Israel is obligated to facilitate the delivery of humanitarian aid to Palestinians by international organizations, including the U.N.

"The Israeli government's policy is making it increasingly difficult for Palestinians to access life-saving assistance and basic services such as health care and education," Norway's foreign minister, Espen Barth Eide, told The Associated Press.

Meanwhile, at the U.N.'s regular Security Council meeting on the Middle East -- this month open to all U.N. members -- speakers supported UNRWA and virtually all called for immediate cease-fires in Gaza and Lebanon.

U.S. Ambassador Linda Thomas-Greenfield expressed deep concern at the Israeli legislation, saying, "right now there is no alternative to UNRWA when it comes to delivering food and other life-saving aid in Gaza."

She also called on Guterres "to create a mechanism to review and address allegations that UNRWA personnel have ties to Hamas and other terrorist groups."

U.N. spokesman Dujarric said the U.N.'s internal watchdog is working on that. He said a letter from the Israeli government last week raising specific undisclosed issues is also being looked at "extremely seriously."

U.S. State Department spokesman Matthew Miller went further, warning that the Israeli legislation "poses risks for millions of Palestinians who rely on UNRWA for essential services."

Miller reiterated that the U.S. opposes the legislation and will be discussing it with Israel in the days ahead. He says there may be consequences under U.S. law and policy if it takes effect, referencing a letter that Secretary of State Antony Blinken and Defense Secretary Lloyd Austin sent to their Israeli counterparts saying humanitarian aid must increase or the country risks losing military assistance.