In a Wall Street Journal op-ed, Biden wrote, “[If] Iran succeeds in significantly escalating its assault on Israel, the US could be drawn in.”

“Israel is our strongest partner in the Middle East; it’s unthinkable that we would stand by if its defenses were weakened and Iran was able to carry out the destruction it intended this weekend,” the US president wrote.

“We can make that outcome less likely by replenishing Israel’s air defenses and providing military aid now, so its defenses can remain fully stocked and ready.”

Biden’s appeal has come just days after Iran launched hundreds of missiles and drones on Sunday, in retaliation for a deadly Israeli bombing of the Iranian consulate in Syria’s capital, Damascus, earlier this month.

Top Israeli officials have said they intend to hit back at Iran after Sunday’s attack, despite calls from the Biden administration and other Western nations to avoid escalation.

Even as regional tensions have surged, the international community has intensified its appeals to the US and other Western nations to condition financial support for Israel upon an increased flow of humanitarian support into the Gaza Strip.  More than 33,800 Palestinians have died since Israel began its siege and blockade of the coastal strip in early October and United Nations officials have warned that the Strip is on the brink of famine.

Supplemental funding bill

While public criticism of the Biden administration’s support for Israel is growing, the country — which receives $3.8bn in US aid annually — has continued to enjoy strong bipartisan support among Washington legislators.

Still, a $95bn bill that would provide an additional $14bn in assistance to Israel, as well as billions more for other American allies, such as Ukraine and Taiwan, has stalled in Congress.

The US Senate passed the legislation — known as the supplemental funding bill — in February. But US House Speaker Mike Johnson has blocked the measure in the House of Representatives, bowing to pressure from hardline, conservative members of his own Republican Party.

A faction of the GOP has argued that the legislation does not do enough to address immigration at the US’s southern border, while other Republicans express concern about US funding for Ukraine’s fight against Russia’s invasion that began more than two years ago and shows no signs of ending.

For a bill to become law in the US, it must be approved by both chambers of Congress and signed by the president.

Since Iran’s attacks on Sunday, Johnson has faced growing pressure on Capitol Hill to bring the supplemental funding bill to the floor for a vote.

“Time is of the essence, and we must ensure critical aid is delivered to Israel and our other democratic allies facing threats from our adversaries around the world,” dozens of US lawmakers wrote in a letter to Johnson earlier this week.

Amid the growing pressure, Johnson wrote in a letter to House legislators on Wednesday that the text of three bills providing assistance to Ukraine, Israel and the Asia Pacific would be filed “soon today”.

A fourth bill with “other measures to confront Russia, China and Iran” will be posted later in the day, he said.

“We expect the vote on final passage on these bills to be on Saturday evening,” Johnson added.

It remains unclear if the bills will garner enough support to pass.

Most Democrats have previously rejected breaking down the foreign assistance bill by country, fearing that Republicans would pass the Israel portion and stall the aid to Ukraine.

But after the Iranian attack, it is unclear whether the Democrats, who control the Senate, would agree to an Israel-only aid bill.

‘Pivotal moment’

In his Wall Street Journal op-ed, President Biden wrote that while both Israel and Ukraine can defend themselves, “they depend on American assistance, including weaponry, to do it. And this is a pivotal moment.”

The supplemental funding bill, Biden added, “shouldn’t be held hostage any longer by a small group of extreme Republican House members”.

Pentagon chief Lloyd Austin also stressed the importance of passing the foreign aid proposal.

“The most important thing that we can do right now is to pass the supplemental,” Austin told US legislators during a briefing on Capitol Hill on Wednesday morning.

Doing that, he said, “will provide us the opportunity to continue to provide security assistance to Israel in the form of air defence interceptors, munitions and things that it critically needs to be able to defend itself”.