Biden hailed the passage of the law as a “good day for world peace”, saying that the measure makes the United States safer.
The package will provide Israel with $17bn in additional aid despite growing calls for restricting US assistance to the country over abuses in Gaza, where the Israeli military has killed more than 34,000 Palestinians.
However, the US president framed the new assistance as an effort to help Israel protect itself from attacks against Iran.
“My commitment to Israel – I want to make clear again – is ironclad,” Biden told reporters. “The security of Israel is critical.”
Palestinian rights advocates were quick to denounce the measure, stressing that Israel stands accused before the International Criminal Court of committing genocide against Palestinians.
“It is beyond unconscionable that Congress and President Biden are sending the Israeli military billions of dollars worth of weapons – with no strings attached – to massacre, starve, and expel Palestinian civilians,” IfNotNow, a youth-led progressive Jewish group, said in a statement.
The US Senate approved the bill on Tuesday in a 79-18 vote. Days earlier, the House of Representatives also adopted the measure.
Late on Tuesday, US Senator Bernie Sanders decried the approval of the supplemental foreign funding bill, calling it a “dark day” for the US Senate. He added that Washington should not fund right-wing Israeli Prime Minister Benjamin Netanyahu’s war on Gaza.
“The housing in Gaza is destroyed; the infrastructure in Gaza is destroyed; the health care system in Gaza is destroyed; the educational system in Gaza is destroyed. Enough is enough,” Sanders said in a statement.
The measure had stalled in Congress for months amid competing political agendas.
Some Republicans have expressed growing scepticism about sending more taxpayer dollars to Ukraine as the Russian invasion of the country grinds on more than two years after it began. But Democrats insisted on passing the bill to provide foreign aid to Ukraine and Israel together.
On Wednesday, Biden stressed the importance of the new law and its implications for the battlefield in Ukraine, where Russian forces have made some gains in recent months.
“Now, Americans are going to send Ukraine the supplies they need to keep them in the fight,” he told reporters.
The law allocates $61bn for Ukraine. It also sets aside $9bn for humanitarian assistance around the world, some of which can go to Gaza.
“We’re going to immediately secure that aid and surge it, including food, medical supplies, clean water,” Biden said. “And Israel must make sure all this aid reaches the Palestinians in Gaza without delay.”
Israel has been imposing a siege in Gaza, severely restricting the entry of food and other vital supplies, bringing the territory of more than 2 million people to the verge of famine.
In a statement on April 4, Biden rebuked Israel, suggesting that Washington would reconsider its support for the offensive in Gaza if the Israeli government does not allow more aid and take steps to protect civilians in the territory.
Since then, Israel has pushed on with its blockade and intensified its attacks on Gaza. This week, more than 300 bodies were discovered in mass graves near the Nasser Hospital in Khan Younis, where the Israeli army had recently conducted an operation.
But the Biden administration has muted its criticism of Israel as tensions between the US ally and Iran intensified in recent weeks. Instead, Washington has repeatedly asserted that its support of Israel remains “ironclad”.
Iran had launched hundreds of drones and missiles against Israel on April 13 in retaliation for a deadly Israeli air raid against Tehran’s consulate in Damascus. Pentagon officials say that US forces in the region helped Israel shoot down most of the Iranian projectiles.
On Wednesday, Biden stressed US support for Israel against Iran. “I will always make sure that Israel has what it needs to defend itself against Iran and terrorists it supports,” he said.