Joe Biden is committing an apparent violation of U.S. law by continuing to send military assistance to Israel while the nation blocks American aid for Gaza, 25 prominent humanitarian and human rights organizations argued in a Tuesday letter to the U.S. president.

In the letter, shared exclusively with HuffPost, the groups cited Bidens decisions in recent days to airdrop aid into Gaza and launch a complex plan to build a floating pier to provide food to people there, some of whom have begun dying of malnutrition and dehydration, as an acknowledgment that Israel is impeding the delivery of crucial U.S. supplies.

Both efforts are the latest implicit recognition of Israels severe restrictions on humanitarian access amid extraordinary human suffering, reads the message, which was delivered to the U.S. National Security Council. Your administration has now publicly recognized what humanitarian organizations have reported for months: that the government of Israel is obstructing the delivery of humanitarian aid to starving Palestinians.

The letter came after eight senators also sent Biden a missive saying Netanyahu is breaching laws governing U.S. military aid.

At question is Section 620I of the Foreign Assistance Act , which says that presidents cannot provide military aid to foreign countries if they know those nations are barring the delivery of U.S. humanitarian relief. In the letter, the groups argued that Biden is violating the law by refusing to end unconditional arms transfers and other support for Israels ongoing deadly offensive in Gaza, which has so far killed more than 30,000 Palestinians, per local authorities.

The Biden administration has repeatedly said that it and Israel are abiding by U.S. laws in their actions in Gaza, and challenged demands for probes of Israeli actions and potential U.S. complicity in war crimes.

The Tuesday statement represents a striking accusation from well-respected groups, ranging from rights watchdogs like Amnesty International and the Center for Civilians in Conflict, or CIVIC, to major aid bodies such as Oxfam America, the Norwegian Refugee Council and Refugees International. It will likely intensify conversations about the aid statute among key policymakers as well as frustration among critics of Bidens Gaza policy.

Sens. Chris Van Hollen (D-Md.) and Bernie Sanders (I-Vt.) and Rep. Jim McGovern (D-Mass.) have recently urged Biden to invoke the law to force Israel to change its aid approach for fear of losing irreplaceable U.S. military backing.

About three weeks ago, I asked senior State Department officials to tell me why this law has not been applied, Van Hollen said on the Senate floor on Feb. 12. I havent gotten an answer.

In February, Sanders and 17 Democratic senators supported legislation from Van Hollen that cited Section 620I and would have required Biden to secure assurances from partner countries, like Israel, that they will fully cooperate with U.S. attempts to distribute aid globally. The Biden administration drew on Van Hollens bill to roll out a new policy governing arms transfers to nations including Israel. But analysts say it will do little to help Gaza today and could be an empty promise in the long run.

Well-known former Sen. Patrick Leahy (D-Vt.) last week told The Independent that he believes current U.S. aid for Israel is violating a different law he championed barring assistance for military units committing major human rights abuses.

The prospect of applying Section 620I during international conflicts has previously arisen twice but it has never been fully implemented.

Congress passed the law in the 1990s, when Turkey was restricting humanitarian assistance to Armenia as it feuded with Azerbaijan, a Turkish ally. Legislators pushed for Section 620I to be applied to Turkey a member of NATO, which works closely with the U.S. military and then-President Bill Clintons administration acknowledged that the statute was relevant, but issued a waiver to maintain military aid despite Turkish aid interference, as Brian Finucane, a former State Department lawyer, noted on X.

And in 2017, under scrutiny from Sen. Todd Young (R-Ind.), then-State Department legal adviser nominee Jennifer Newstead said that the law could apply to Saudi Arabia, which was receiving U.S. military assistance as it waged war in Yemen and limited how much aid entered that country. Newstead ultimately served as States top lawyer from January 2018 to April 2019.

But Finucane added in a later post that the Biden administration may be loath to even acknowledge a violation while the International Court of Justice is still weighing a case on whether Israel is committing genocide in Gaza; the U.S. could end up strengthening a suit that might implicate U.S. officials who are enabling the campaign. HuffPost has previously revealed that several U.S. government agencies are tracking whether Israels Gaza policy involves violations of international and U.S. law.

Regardless of the Biden administrations willingness to acknowledge the law, clearly worsening conditions in the Palestinian enclave mean it cannot be ignored for good, activists and analysts argue.

Restrictions are not isolated instances but the policy of the government of Israel, the Tuesday letter tells Biden, citing repeated statements by Israeli Prime Minister Benjamin Netanyahu, as well as Israels denials of humanitarian requests and attacks on civilians seeking aid.