The delivery comprised 1,800 bombs weighing 2,000 pounds (907 kilograms) each and 1,700 bombs weighing 500 pounds, an official informed CBS News.
The US official stated that Israel hasn't adequately addressed American concerns regarding the humanitarian needs of civilians in Rafah.
An Israeli military spokesperson sought to downplay the US decision.
Daniel Hagari, spokesperson for the Israel Defense Forces, remarked during a press briefing that the US has offered "unprecedented" security assistance since the war's outset, noting that disagreements between the allies are resolved "privately and pragmatically."
"We are accountable for Israel's security interests and heed the US interests in the region," he emphasized.
During the night, additional Israeli airstrikes hit the Gaza Strip, following Israeli forces, backed by tanks, seizing control of the Palestinian side of the vital Rafah crossing along the Egyptian border.
The bombardment centered heavily on Rafah, with local medical personnel reporting the deaths of seven members of a single family in one strike.
Rafah has served as a crucial entry point for aid and the sole exit for those able to escape since the commencement of the conflict between Israel and Hamas last October.
Although the crossing remained shut on Wednesday morning, the Israeli military announced the reopening of the nearby Kerem Shalom crossing, which had been closed for four days due to Hamas rocket attacks.
On Monday, the Israeli military instructed tens of thousands of civilians to evacuate eastern parts of Rafah city ahead of what it termed a "limited" operation to eradicate Hamas militants and dismantle infrastructure.
Efforts persist to broker a ceasefire, coupled with the release of Israeli captives and Palestinian detainees. In Cairo, Israeli and Hamas delegations have resumed negotiations through intermediaries.
"The stance of the US has been that Israel should refrain from initiating a significant ground operation in Rafah, where over a million individuals have sought refuge without alternative accommodations," stated a senior official from the US administration to CBS, the US partner of the BBC, on Tuesday.
"We've been actively engaged in discussions with Israel through our Strategic Consultative Group framework, focusing on how they can address the humanitarian needs of civilians in Rafah and adjust their strategies against Hamas compared to other areas in Gaza.
"These conversations are ongoing and haven't fully addressed our concerns. As Israeli leadership appeared to approach a pivotal decision regarding such an operation, we commenced a thorough review of proposed transfers of specific weaponry to Israel that could potentially be utilized in Rafah. This evaluation commenced in April.
"As a consequence of this review, we decided to halt one shipment of weaponry last week. The shipment comprises 1,800 2,000-pound bombs and 1,700 500-pound bombs," added the unnamed official.
"We are particularly concerned about the utilization of the 2,000-pound bombs and their potential impact in densely populated urban environments, similar to what we've observed in other parts of Gaza. We haven't reached a final decision on how to proceed with this shipment."
The official also mentioned that "we're currently continuing the review process for certain other cases at the State Department, including JDAM kits. None of these cases involve imminent transfers; they pertain to future deliveries."
The official emphasized that these shipments were not linked to last month's historic $17 billion military aid package but were sourced from "previously allocated funds."
The larger 2,000-pound bombs are likely Mk-84s or possibly BLU-109s - or both.
The former is a cost-effective, versatile munition, while the latter is a bunker-busting bomb designed for targeting hardened or subterranean installations. Both can be equipped with JDAM kits, enabling precision strikes using satellite navigation. Laser guidance kits are also an option.
These bombs can be calibrated for high accuracy, even to within a few meters. However, the risk of causing "collateral damage" is substantial in densely populated urban environments like Gaza, which is the primary concern. The smaller 500-pound bombs can also be outfitted with guidance systems deployed from aircraft.
While the precise manner in which Israel employs these weapons is unknown, social media posts from the Israeli Air Force frequently depict F-16 and F-15 jets loaded with JDAMs for operations.
It's important to note that such weaponry wouldn't only be utilized in Gaza but also against targets in southern Lebanon associated with the Iran-backed Hezbollah, engaged in nearly daily border skirmishes with Israeli forces since the outset of the Gaza conflict.
The arms withheld by the US pertain to a forthcoming delivery, thus unlikely to have an immediate impact. However, considering Israel's ongoing intensive bombing, it's probable that future strikes will be affected fairly soon.
This action signals Washington's escalating unease regarding Israel's offensive in Gaza.
Israel launched the offensive with the aim of eradicating Hamas following the group's incursion into southern Israel on October 7, resulting in approximately 1,200 casualties and 252 individuals taken hostage.
Since then, more than 34,780 casualties have been reported in Gaza, according to the health ministry governed by Hamas.
A November agreement saw Hamas releasing 105 hostages in exchange for a week-long ceasefire and the release of around 240 Palestinian detainees from Israeli prisons. Israel asserts that 128 hostages remain unaccounted for, with 36 presumed dead.
