The U.S. reportedly put a hold last week on a weapons shipment to Israel ― a stunning diplomatic shift as Prime Minister Benjamin Netanyahu prepares to go against the Biden administration’s warnings and move forward with a military invasion of the Gazan city of Rafah.

The alleged pause in large shipment of offensive weapons appears to be the first instance of the Biden administration withholding U.S.-made arms from Israel since Oct. 7, when Netanyahu launched a military campaign on Gaza in response to an attack by Hamas militants that killed about 1,200 people and took around 250 hostage, roughly 100 of whom are suspected to still be alive in captivity.

The delivery halt was first reported on Sunday by Axios, citing two unidentified Israeli officials who said the incident raised concerns internally, and led officials within Netanyahu’s government to try and figure out why the U.S. was holding the shipment. MSNBC confirmed the halt on Monday, citing two senior Biden administration officials familiar with the decision.

The White House, the Pentagon and the Israeli government did not immediately respond to HuffPost’s request for confirmation of the alleged halt, and the State Department declined to comment. On Monday, National Security Council spokesman John Kirby did not confirm nor deny to reporters the shipment hold.

Since Israel’s current military campaign began seven months ago, health officials in the Palestinian territories say soldiers have killed more than 34,000 people, displaced most of the population, destroyed important infrastructure like hospitals and universities, detained and tortured civilians, and created a widespread famine by blocking most humanitarian aid from entering the enclave. Israeli troops and settlers have also been attacking Palestinians in the occupied West Bank, which is not governed by Hamas.

Since Oct. 7, the U.S. has given unconditional support to Israel, sending many of the weapons that soldiers end up using to bomb Gaza. President Joe Biden started a trend of warning Israel about its behavior in Gaza while imposing no consequences on the country for ignoring said warnings ― making this reported hold in weapons shipment a significant elevation in tensions between Biden and Netanyahu.

Biden has faced strong opposition both domestically and globally for continuing to support Israel, even as the country stands accused before the International Court of Justice of committing genocide against Palestinians, an allegation it vehemently denies.

Students across the U.S. have been met with police brutality for campus protests against Israel’s offensive and the Biden administration’s role in it ― demonstrations of a scale and intensity arguably not seen in the U.S. since the Vietnam War ― while a growing number of lawmakers are calling for the U.S. to put conditions on its billions in military aid to Israel.

After more than a dozen senators demanded assurances that all countries receiving U.S. weapons comply with international and U.S. law prohibiting violence against civilians and attempts to block humanitarian aid, Biden issued a policy in February that requires federal agencies to report to Congress by May 8 on whether they believe Israel is violating those laws.

Netanyahu has repeatedly made it clear that the Israeli military will move forward with its plan to launch a ground offensive on Rafah, Gaza’s southernmost city where more than a million Palestinians are currently taking refuge. Soldiers have already been raining bombs on Rafah for weeks, but the prime minister said in recent days that Israel will invade the city regardless of whether his government reaches a deal with Hamas for the release of hostages and a temporary cease-fire.

The U.S. and the international community have vocally opposed a Rafah invasion due to the high civilian casualties likely to result from such a siege, with Secretary of State Antony Blinken telling Netanyahu last week that a “major military operation” in Rafah would negatively affect U.S.-Israel relations and U.S. policy toward the offensive in Gaza.

“In the terrible Holocaust, there were great world leaders who stood by idly,” Netanyahu said on Sunday in commemoration of Holocaust Remembrance Day. “Therefore, the first lesson of the Holocaust is: If we do not defend ourselves, nobody will defend us. And if we need to stand alone, we will stand alone.”