In the findings of a state department report - known as the national security memorandum - the Joe Biden administration said it has found "reasonable" evidence to conclude that its ally had breached international law, Sky News reports.
A report by the United States government has said that Israel's use of US-provided weapons in Gaza likely violated international humanitarian law, but without finding specific violations that would require a military aid ban.
In the findings of a state department report - known as the national security memorandum - the Joe Biden administration said it has found "reasonable" evidence to conclude that its ally had breached international law, Sky News reports.
The Israeli military is facing increased international scrutiny as its military operation in Gaza enters its eighth month, claiming the lives of more than 34,000 Palestinians, mostly civilians.
In February, President Joe Biden ordered the Pentagon and the State Department to “obtain certain assurances” over Israel’s use of US-made weapons and to report back to Congress. A summary of the findings was released to the public on Friday.
But it added it was unable to link specific US weapons to individual Israeli strikes.
The report said: "Given Israel's significant reliance on US-made defence articles, it is reasonable to assess that defence articles have been used by Israeli security forces since 7 October in instances inconsistent with its international humanitarian law obligations or with established best practices for mitigating civilian harm."
It added that while Israel has the knowledge, experience and tools to implement the "best practices for mitigating civilian harm in its military operations" evidence from the ground - including high levels of civilian casualties - raise "substantial questions whether the IDF is using them effectively in all cases".
Turning to the issue of aid getting into Gaza, the US government report said it does not currently assess that the Israeli government is prohibiting or restricting the transport or delivery of aid.
Crucially, the report stops short of saying that Israel has violated the terms under which it is able to use US weapons to carry out its offensive in Gaza.
Israel declared war on Hamas in Gaza following the militant group’s deadly October 7 incursion, which claimed over 1,200 lives, while hundreds of Israelis were taken hostage.
Although IDF tanks rolled into the outskirts of Rafah on Monday, with Israeli troops securing parts of the city, but Biden believes that Israel’s “limited” operation has yet to cross Washington’s red line.
On Friday, Israel’s war cabinet approved a “measured expansion” of the ground operation in Rafah, with Prime Minister Benjamin Netanyahu pledging to continue the military campaign and “fight with our fingernails” if the US halts in the supply of weapons.