As the Biden administration increasingly clashes with Israeli leaders over the war in Gaza, a question that often arises is whether U.S. officials will try to exercise some form of harder leverage as Israel ignores their pleas.

They could do so, critics say, to try to get Israel to let more humanitarian aid into Gaza as it teeters on the brink of famine, to scale back its military campaign or to refrain from invading the Gaza Strip city of Rafah, where many civilians have fled.

Since the Hamas terrorist attacks on Oct. 7, in which about 1,200 Israelis were killed and about 240 taken hostage, Israel’s strikes have killed more than 30,000 Palestinians, according to the Gaza Health Ministry. President Biden has tried to influence Prime Minister Benjamin Netanyahu behind the scenes while showing strong support for Israel. Yet confrontations loom.

Israeli officials are expected to meet with their U.S. counterparts next week in Washington to hash out opposing opinions on plans to invade Rafah. And a growing number of former American officials say Mr. Biden has to start exercising leverage to shift Israel away from what they call its disastrous war.

The Biden administration has increasingly spoken of the humanitarian crisis in Gaza, including mentioning it in a draft resolution on the war that it presented to the United Nations Security Council this week. The resolution called for an “immediate and sustained cease-fire” if Hamas released all hostages — a reiteration of the administration’s position, but with firmer language. Russia and China vetoed the resolution on Friday. Many nations have argued for a cease-fire with no conditions.

Mr. Biden would not be the first president to use hard levers if he chooses to do so. Four administrations, from Gerald R. Ford’s to George H.W. Bush’s, all withheld some form of aid or diplomatic agreement or firmly threatened that they would, said Martin S. Indyk, a special envoy for Israeli-Palestinian negotiations in the Obama administration.

“In recent years, the willingness to use the aid relationship for leverage has dramatically diminished,” he said. “The relationship of dependence is there, just waiting to be used.”

U.S. leverage with Israel falls into three main categories. We’ll start with weapons aid, the most significant one.

Weapons shipments

The United States is by far the largest supplier of military aid to Israel. In 2022, the aid amounted to $3.3 billion. Since the war began, the Biden administration has pushed Congress to pass funding legislation that includes $14 billion in additional aid, but that has been stalled mainly for reasons unrelated to the war.

Israel is depleting much of its munitions and needs the American shipments. The U.S. government is working to approve new arms orders and has accelerated orders that were in the pipeline before the war began.

Between October and around Dec. 1, 2023, the United States transferred about 15,000 bombs and 57,000 artillery shells to Israel, U.S. officials said late last year. From Dec. 1 to now, those total transfer numbers have increased by about 15 percent, a U.S. official said.

When Yoav Gallant, Israel’s defense minister, meets with Defense Secretary Lloyd J. Austin III in Washington next week, the official said, Mr. Gallant is expected to press for expedited approval of earlier requests for F-15 fighter jets worth billions and for a large batch of GPS-guided munitions kits. Mr. Gallant could also raise a potential purchase of more F-35 fighter jets, the official said.

More than 100 arms transfers have taken place since October, but almost all have occurred without notifying Congress because of loopholes in disclosure rules.

Last December, Secretary of State Antony J. Blinken twice invoked a rarely used emergency authority to send tank ammunition and artillery shells to Israel without congressional review. Those were the only two times the administration has given public notice of government-to-government military sales to Israel since October.

If Mr. Biden ordered a slowdown or halted some or most arms transfers, Israeli leaders would get the message, current and former U.S. officials said.

Mr. Biden has signaled he is aware of the concerns. He issued a memorandum in February that laid out standards of compliance for all countries receiving U.S. weapons, including adhering to international humanitarian law, and required the countries to provide signed letters to the State Department promising they would abide by the rules.

Some advocates of the harder approach argue Mr. Biden should declare that Israel is in violation of a section of the Foreign Assistance Act of 1961, which says the United States cannot provide arms or other aid to a country that “prohibits or otherwise restricts, directly or indirectly, the transport or delivery of United States humanitarian assistance.” Eight Democratic senators sent a letter to Mr. Biden on March 11 urging him to do this.

They noted that the law does not preclude the U.S. government from providing defensive supplies to a country violating the law, such as interceptor missiles for Israel’s Iron Dome.

Josh Paul, a former official in the State Department’s political-military bureau, which oversees weapons transfers, said if Mr. Biden were to take this action, Israel would face a hard choice between continuing its campaign in Gaza or saving munitions for the deterrence it needs to maintain against other hostile forces, notably Hezbollah and Iran.

“A cutoff of some arms would force Israel to think about what is the urgent thing it needs for its national security — is it using as many weapons as possible in Gaza?” said Mr. Paul, who resigned in October in protest of the administration’s policy on the war.

The State Department has not approved a request by Israel for 24,000 assault rifles, an order that The New York Times reported in November was being scrutinized by some American lawmakers and State Department officials because of the potential for the rifles to fuel extremist settler violence against Palestinians in the West Bank.

Many arms transfers involve weapons systems that Israel bought and paid for years ago, and are coming up for delivery soon, one former U.S. official and one current U.S. official said. At any given time, there are hundreds, possibly thousands, of open contracts for sales to Israel, the current U.S. official said. The two Americans argued that it could be difficult to slow or suspend specific sales, and that such actions could expose the U.S. government to legal liability under contract law.

The former American official argued that halting transfers could send a message to Iran and its partners that the United States was willing to abandon Israel in a time of need. But this official was not aware of any formal intelligence assessment about the effect of such an action.

Senator Jack Reed, a Rhode Island Democrat who heads the Armed Services Committee, made it clear this week that he opposed putting conditions on military assistance to Israel to try to influence its operations in Gaza.

“This is not the time to talk about conditioning,” Mr. Reed said. “We are Israel’s ally. They are our ally.”

The diplomatic shield

The United States has been a staunch ally of Israel in international institutions, where many countries have expressed outrage over the civilian casualties in Gaza.

This is especially true at the U.N. The Biden administration has shielded Israel from diplomatic condemnations and from resolutions calling for Israel to immediately halt or suspend its war.

Less U.S. support for Israel would open the country to more powerful formal denunciations in the U.N.

Since the war began, the United States has exercised its veto power as a U.N. Security Council member to block three council resolutions calling for an immediate cease-fire with no conditions.

Its own recent resolution that called for a cease-fire tied to the release of all hostages was blocked by Russia and China on Friday.

The United States has also been a vocal critic of the genocide case brought against Israel by South Africa in the International Court of Justice at The Hague. The court made an interim ruling in January that called on Israel to prevent its forces from engaging in any acts that would violate the 1948 Genocide Convention.

Sanctions

The Biden administration has refrained from imposing sanctions on Israeli officials, but may be giving itself more leeway to do so. Such measures would probably be aimed more at reining in Israel’s policies and actions in the West Bank, where the current government has encouraged the expansion of settlements at a cost to Palestinians, than at curbing military operations in Gaza.

In late February, Mr. Blinken announced that the Biden administration considered new Israeli settlements in Palestinian territories to be “inconsistent with international law” — a reversal of a Trump administration policy and a return to a longstanding State Department legal assessment.

On March 14, the department imposed sanctions on three Israeli settlers in the West Bank whom it accused of “extremist violence” against Palestinians. The Biden administration took similar action against four Israelis on Feb. 1.

Harsh U.S. sanctions have failed to change the behavior of leaders in a range of countries, from Russia to Iran to North Korea. But sanctions on Israeli officials, or the threat of them, could have a greater effect because Israel is a U.S. partner, and because many Israeli officials have assets and family members in the United States and travel there often.

Farnaz Fassihi contributed reporting from the U.N.