The United States paused a shipment of bombs to Israel last week over fears it would invade the southern Gaza city of Rafah, an official said Tuesday, marking the first time in the conflict that President Joe Biden has squeezed military aid to the key US ally.
Washington halted the load of 1,800 2,000-lb (907 kg) bombs and 1,700 500-lb (226 kg) bombs after Israel had not "fully addressed" US concerns about a major ground operation, a senior administration official said.
News of the move comes as the White House blasted the "unacceptable" closure of the Rafah border crossing with Egypt after Israel sent tanks in earlier Tuesday -- while holding out hope for a ceasefire with Hamas.
The pausing of weapons marks the first time that Biden has acted on the warning that he gave Prime Minister Benjamin Netanyahu in April that US policy on Gaza would depend on how Israel treated civilians.
The US official said Biden's administration made the decision on the weapons when it appeared Israel was on the verge of a major ground operation into Rafah, which Washington has strongly opposed as more than a million people are sheltering there.
Israeli and US officials had been discussing alternatives but "those discussions are ongoing and have not fully addressed our concerns," the senior US official said, speaking on condition of anonymity.
"As Israeli leaders seemed to approach a decision point on such an operation, we began to carefully review proposed transfers of particular weapons to Israel that might be used in Rafah. This began in April."
The US official said Washington was "especially focused" on the use of the heaviest 2,000-lb bombs "and the impact they could have in dense urban settings as we have seen in other parts of Gaza."
"We have not made a final determination on how to proceed with this shipment," the official said.
The US State Department is still reviewing other weapons transfers, including the use of precision bomb kits known as JDAMs, added the official.
The White House said earlier that Israel had promised the military thrust into Rafah earlier Tuesday was a "limited operation" and not the feared full-scale invasion.
While facing a difficult reelection battle in November against Republican rival Donald Trump, Biden has come under growing domestic pressure over his support for Israel, with widespread protests at US universities leading to police crackdowns and thousands of arrests.
Republicans have also piled on the political pressure, and US House Speaker Mike Johnson -- who has repeatedly claimed the protests are anti-Semitic -- criticized on Tuesday any move to limit military aid.
"Just when we thought it was only university presidents who are caving into the absurd demands of the pro-Hamas students, the president himself has now reportedly halted ammunition shipments to Israel," Johnson said to reporters ahead of the official US announcement.
Johnson said it was "undermining" a huge aid package with military support for Israel and Ukraine that Congress passed after months of delays in April -- although the US official said the halted shipment was not linked to that package.
Biden's move does however turn the screw on Israel to end the seven-month conflict and to take more action on the humanitarian situation in Gaza.
"The crossings that have been closed need to be reopened, it is unacceptable for them to be closed," White House Press Secretary Karine Jean-Pierre told a briefing earlier Tuesday over Israel's seizure of the Rafah crossing.
Meanwhile ceasefire talks involving Israel, Hamas, the United States, Qatar and Egypt resumed on Tuesday.
"A close assessment of the two sides' positions suggests that they should be able to close the remaining gaps, and we're going to do everything we can to support that process," US National Security Council spokesman John Kirby said.
The war was sparked by Hamas's October 7 attack on Israel, which resulted in the deaths of more than 1,170 people, mostly civilians, according to an AFP tally of Israeli official figures.
Israel launched a retaliatory offensive that has killed at least 34,789 people in Gaza, mostly women and children, according to the Hamas-run territory's health ministry.
