THE HAGUE, Netherlands (AP) — A Palestinian diplomat told the United Nations’ top court on Monday that Israel is killing and displacing civilians and targeting aid workers in Gaza, in a case that Israel criticized as part of its “systematic persecution and delegitimization.”

Israel denies deliberately targeting civilians and aid staff as part of its war with Hamas and did not attend the hearing at the International Court of Justice.

In The Hague, Palestinian Ambassador to the Netherlands Ammar Hijazi accused Israel of breaching international law in the occupied territories.

“Israel is starving, killing and displacing Palestinians while also targeting and blocking humanitarian organizations trying to save their lives,” he told the court.

The hearings are focussed on a request last year from the U.N. General Assembly, which asked the court to weigh in on Israel’s legal responsibilities after the country blocked the U.N. agency for Palestinian refugees from operating on its territory.

Lawyer Paul Reichler, representing the Palestinians, told judges that one of the Geneva Conventions “not only lays down that the occupying power must agree to relief schemes on behalf of the population, but insists that it must facilitate them by all the means at its disposal.”

U.N. Undersecretary-General for Legal Affairs Elinor Hammarskjöld said that “measures taken by the occupying power to ensure its security must be exercised in a manner that would not deny impartial humanitarian organizations such as the United Nations the ability to carry out relief schemes.”

Hearings opened as the humanitarian aid system in Gaza is nearing collapse. Israel has blocked the entry of food, fuel, medicine and other humanitarian supplies since March 2. It renewed its bombardment on March 18, breaking a ceasefire, and seized large parts of the territory, saying it aims to push Hamas to release more hostages. Despite the stepped-up Israeli pressure, ceasefire efforts remain deadlocked.

The World Food Program said last week its food stocks in the Gaza Strip have run out, ending a main source of sustenance for hundreds of thousands of Palestinians as many families are struggling to feed their children.

What will happen in the court?

The United Nations was the first to address the court on Monday, followed by Palestinian representatives. In total, 40 states and four international organizations are scheduled to participate.

Israel ally the United States is scheduled to speak on Wednesday.

The court will likely take months to rule. Experts say the decision, though not legally binding, could profoundly impact international jurisprudence, international aid to Israel and public opinion.

“Advisory opinions provide clarity,” Juliette McIntyre, an expert on international law at the University of South Australia, told The Associated Press. Governments rely on them in international negotiations and the outcome could be used to pressure Israel into easing restrictions on aid.

Whether any ruling will have an effect on Israel, however, is unclear. Israel has long accused the United Nations of being unfairly biased against it and has ignored a 2004 advisory ruling by the ICJ that found its West Bank separation barrier illegal.

Palestinian U.N. envoy Riyad Mansour told reporters that the Palestinians were seeking justice and want an advisory opinion “to allow humanitarian assistance to reach our people at the scale that they need, led by UNRWA, which is the brilliant, most beautiful success story of multilateralism under United Nations.”

While Israel was not in court, Foreign Minister Gideon Saar hit back at the case.

“I accuse UNRWA, I accuse the U.N., I accuse the secretary-general and I accuse all those that weaponized international law and its institutions in order to deprive the most attacked country in the world, Israel, of its most basic right to defend itself,” he told a news conference in Jerusalem. He said the court hearing was part of a “systematic persecution and delegitimization” of his country.

On Tuesday, South Africa, a staunch critic of Israel, will present its arguments. In hearings last year in a separate case at the court, the country accused Israel of committing genocide against the Palestinians in Gaza — a charge Israel denies. Those proceedings are still underway.

Israel’s troubled relations with UNRWA

Israel’s ban on the agency, known as UNRWA, which provides aid to Gaza, came into effect in January. The organization has faced increased criticism from Prime Minister Benjamin Netanyahu and his far-right allies, who claim the group is deeply infiltrated by Hamas. UNRWA rejects that claim.

On Monday, Amir Weissbrod, a Foreign Ministry official, accused UNRWA of failing to act before the war against evidence that Hamas had used its facilities, including by digging tunnels underneath them. The official said UNRWA employed 1,400 Palestinians with militant ties. Israel says some of those employees also took part in Hamas’ Oct. 7, 2023, attacks and Weissbrod said at least three of those employees still worked for the U.N. The presentation included videos, documents and pictures of the alleged employees.

While Israel did not attend the hearings in The Hague, the country sent a 38-page document elaborating on Weissbrod’s statement and arguing that the country does not have any legal obligations “towards any third parties” in the occupied territories.

The Oct. 7, 2023, attack in southern Israel killed about 1,200 people and set off the war in Gaza. UNRWA said it fired nine staffers after an internal U.N. investigation concluded that they could have been involved, although the evidence was not authenticated and corroborated.

The Israeli ban doesn’t apply directly to Gaza. But it controls all entry to the territory, and its ban on UNRWA from operating inside Israel greatly limits the agency’s ability to function. Israeli officials say they are looking for alternative ways to deliver aid to Gaza that would cut out the United Nations.

The agency has been providing aid and services — including health and education — to some 2.5 million Palestinians in Gaza, the occupied West Bank and east Jerusalem, as well as 3 million more in Syria, Jordan and Lebanon.

Israel’s air and ground war has killed over 51,000 Palestinians, mostly women and children, according to the Gaza Health Ministry, which does not say how many of the dead were civilians or combatants. Israel says it has killed around 20,000 militants, without providing evidence.