Biden’s Threat to Withhold Arms Over Rafah Sharpens a Problem for Israel

American-made weapons, including heavy bombs, have been essential to Israel’s war effort since the country was attacked by Hamas and other militant groups on Oct. 7. But Mr. Biden has been under growing domestic pressure to rein in Israel’s military as the death toll has risen in Gaza. It is now more than 34,000.

And in his comments on Wednesday in an interview with CNN, Mr. Biden acknowledged for the first time that U.S. bombs had killed innocent civilians in the conflict.

The American concerns have only grown since the Israeli army sent tanks and troops into the eastern part of Rafah on Monday night, taking over the main border crossing between Gaza and Egypt. Israeli forces have stopped short of entering built-up parts of the city, but Mr. Netanyahu and others have signaled that such an operation is necessary to eliminate Hamas battalions there.

On Tuesday, American officials said Mr. Biden had withheld 1,800 2,000-pound bombs and 1,700 500-pound bombs that he feared could be dropped on Rafah. The administration was reviewing whether to hold back future transfers, including guidance kits that convert so-called dumb bombs into precision-guided munitions, the officials said.

In addition to the bombs, Mr. Biden said the United States would not supply artillery shells if Israel invaded population centers in Rafah.

Gilad Erdan, the Israeli ambassador to the United Nations, described the Biden administration’s decision as “very disappointing” and “frustrating.”

“We have a cruel enemy here,” he said. “Is this the time to put restrictions on Israel’s weapons?”

Nadav Eyal, a prominent columnist for a centrist Israeli newspaper, said Mr. Biden had essentially decided to declare an end to the war. Writing on the social media platform X, he called it “the most serious clash between an American administration and the government of Israel since the first Lebanon war.”

During that conflict, which began in 1982, the Reagan administration suspended the delivery of cluster-type artillery ammunition and other weapons to Israel.

“We’ve reached a boiling point,” Mr. Eyal said in a follow-up interview. “Issues that have been negotiated behind closed doors have now been brought into the public view in a very ugly way.”

Some analysts, however, downplayed the significance of the crisis, arguing it wasn’t as bad as past fissures between the United States and Israel. The rupture in relations over the Iran nuclear deal in 2016 was “much worse,” said Mr. Nagel.

Amid the tense state of affairs, Israel’s president, Isaac Herzog, thanked the United States for supporting Israel and appeared to lash out at Itamar Ben-Gvir, the national security minister, who had posted on X, “Hamas ♥ Biden.”

“Even when there are disagreements and moments of disappointment between friends and allies, there is a way to clarify the disputes,” Mr. Herzog said.

Myra Noveck and Johnatan Reiss contributed reporting.