An entire generation of Palestinians in the Gaza Strip would "be denied the right to education" if the United Nations Palestinian relief agency UNRWA collapses in the enclave under new Israeli legislation, the head of UNRWA warned on Wednesday.

Israel's parliament passed a law last month that will ban UNRWA from operating in the country when it takes effect in late January. UNRWA Commissioner-General Philippe Lazzarini said its implementation "will have catastrophic consequences."

"In Gaza, dismantling UNRWA will collapse the United Nations humanitarian response, which relies heavily on the agency's infrastructure," he told a U.N. General Assembly committee. "Glaringly absent from discussions about Gaza without UNRWA, is education."

"In the absence of a capable public administration or state, only UNRWA can deliver education to more than 660,000 girls and boys across Gaza. In the absence of UNRWA, an entire generation will be denied the right to education," he said, warning that this would sow "the seeds for marginalization and extremism."

He again pushed U.N. member states to act to prevent the implementation of the Israeli legislation. UNRWA was established in 1949 following the war surrounding the founding of Israel in the previous year. It provides aid, health and education to millions of Palestinians in Gaza, the West Bank and Syria, Lebanon and Jordan.

Israel's ally the United States has described the role of UNRWA in Gaza as "indispensable." U.S. Ambassador to the U.N. Linda Thomas-Greenfield said on Tuesday that it was of urgent importance that Israel pause implementation of the law.

However, the legislation is due to take effect in late January, just days after U.S. President-elect Donald Trump takes office for a second four-year term. If his first term is any indication, Trump is likely to pursue a strongly pro-Israel approach, going even beyond the solid support given by President Joe Biden.

The U.N. Security Council has backed UNRWA and "strongly warned against any attempts to dismantle or diminish" it.

U.N. Secretary-General Antonio Guterres has told Israel that replacing UNRWA in Gaza and the West Bank would be Israel's responsibility as the occupying power. The U.N. views Gaza and the West Bank as Israeli-occupied territory.

"We left Gaza completely in 2005. We disengaged, we gave the keys to the Palestinian Authority," Israel's U.N. Ambassador Danny Danon told reporters after Lazzarini's briefing.

"Now we are in a war after we were attacked and we act according to international law; that's why we provide humanitarian support and we cooperate with many U.N. agencies," he said. "We are willing to cooperate, but not with terrorists."

Israel says UNRWA staff took part in the Oct. 7, 2023, Hamas attack on Israel, which sparked the war in Gaza. The U.N. has said nine UNRWA staff may have been involved and had been fired. A Hamas commander in Lebanon - killed by Israel - was also found to have had an UNRWA job.