Citing two Israeli officials, Axios reported on May 5 that the Biden administration has put a hold on a shipment of U.S.-made ammunition to Israel.

It is the first time since the October 7 attack that the U.S. has stopped a weapons shipment intended for the Israeli military.

The incident raised serious concerns inside the Israeli government and sent officials scrambling to understand why the shipment was held, Israeli officials were quoted as saying.

President Biden is facing sharp criticism among Americans who oppose his support of Israel.  The administration in February asked Israel to provide assurances that U.S.-made weapons were being used by Israel Defense Forces in Gaza in accordance with international law.  Israel provided a signed letter of assurances in March.

The Israeli officials said the ammunition shipment to Israel was stopped last week.

Axios notes that the Pentagon, the State Department and the Israeli Prime Minister's Office didn't immediately respond to questions.

The Biden administration is reportedly highly concerned Israel will invade the southern Gaza city of Rafah where more than one million displaced Palestinians have been taking shelter.

Israeli Prime Minister Benjamin Netanyahu released several statements in recent days saying he intended to order an invasion of Rafah regardless of whether Israel and Hamas reach a deal for the release of hostages being held in Gaza and a ceasefire.

Netanyahu hinted at tensions with the Biden administration in a statement on Holocaust Remembrance Day issued Sunday, according to Axios.

Last Wednesday U.S. Secretary of State Antony Blinken reportedly visited Israel and had a “tough” conversation with Netanyahu regarding a possible Israeli operation in Rafah, two sources briefed on the meeting said.

Blinken told Netanyahu during their meeting that “a major military operation” in Rafah would lead to the U.S. publicly opposing it and would negatively impact U.S.-Israel relations.

A day later White House spokesman John Kirby told reporters that Israeli leaders understand that President Biden “is sincere” when he talks about the possibility of changes to U.S. policy regarding the Gaza war “should they move ahead with some sort of ground operation in Rafah that doesn't take into account the refugees.”