In a report to the U.S. Congress on Friday, the State Department raised doubts about whether Israel has in all instances used U.S. military assistance in a manner consistent with U.S. and international law, but it stopped short of a final conclusion and said it was still investigating.

Washington, D.C. On balance, the report said Israeli assurances that it has been using the materiel appropriately were found to be “credible and reliable.” The determination allows the U.S. to continue providing materiel to Israel.

A senior State Department official said the U.S. had not currently assessed that the Israeli government was prohibiting or restricting the transport or delivery of U.S. humanitarian assistance, but it is an ongoing evaluation.

While Israel has the knowledge, experience and tools to implement best practices for mitigating civilian harm in its military operations, the results on the ground, including high levels of civilian casualties, raise substantial questions as to whether its military is using them effectively in all cases, the report said.

The politically sensitive report to Congress came as Israel was pressing ahead with its military operation in Rafah and amid growing concerns about restricted humanitarian aid to Gaza. The Rafah crossing into Egypt has been the main portal for delivery of food and other humanitarian assistance into Gaza.

The U.S. is watching Israel’s operation in Rafah with concern and urges Israel to reopen the Rafah crossing immediately, White House National Security Council spokesperson John Kirby told reporters Friday.

“There’s going to be more suffering, and that’s deeply concerning to us,” Kirby said.

In the past five days, more than 100,000 people have fled Rafah, where more than half the enclave’s population had sought refuge from the fighting, said a senior UNICEF humanitarian coordinator earlier Friday. Israel seized the Gaza side of the Rafah crossing on Tuesday.

Israel’s military campaign has killed nearly 35,000 Palestinians and wounded nearly 80,000, most of them civilians, according to Gaza’s Health Ministry. The offensive was launched following a Hamas terror attack into Israel that killed 1,200 people.

National security memorandum

In February, U.S. President Joe Biden issued a national security memorandum, known as NSM-20, that required the State Department to assess and report to Congress on whether it found Israel’s assurances “credible and reliable” regarding the use of U.S. weapons in ensuring compliance with international and U.S. law.

Israel has provided written assurances to Washington that its use of weapons supplied by the U.S. in the Gaza war has not violated U.S. or international legal standards in its conduct of the war or its treatment of civilians, including the provision of adequate humanitarian assistance.

But analysts said there’s currently no government mechanism to monitor how American weapons are used.

“What we call end-use monitoring is an unfortunate misnomer. It’s basically just checking if a munition is in the hands of a designated end user, rather than how that end user is using this munition,” said Ari Tolany, director of the Security Assistance Monitor program at the Center for International Policy.

“So it’s for this reason that NSM-20 was very reliant on humanitarian and documentary organizations to submit credible allegations of abuses of U.S. weapons, because the U.S. government does not have statutory authority going to be regularly tracking that.”

Others, including the Independent Task Force on the Application of National Security Memorandum-20, a private, volunteer group of policy experts, said the State Department’s assessment that Israeli forces have in some instances used the U.S. weapons in a manner inconsistent with humanitarian law “continues to inch towards reality.”

The task force recommended that Congress conduct strong oversight of arms transfers.

State Department spokesperson Matthew Miller explained that the NSM-20 report examines past events, with the department reviewing various aspects from the previous year up until the time of the report’s submission.

“It goes to questions of intent. It goes to questions of proportionality,” Miller told reporters Thursday.

U.S. opposes full-scale assault

The U.S. has been opposing a full-scale military assault by Israel in Rafah, situated in the southern part of Gaza. Such an operation would endanger the lives of 1.3 million civilians who evacuated from the northern and central areas of the territory to seek safety from Israel’s military response to Hamas militants’ October 7 attack on Israel.

Biden has made clear the U.S. will not make available certain types of military assistance to Israel for its use in a military campaign in Rafah. The Biden administration recently paused bomb shipments to Israel, sending a political message to its ally.