The U.S. in May paused a shipment of 2,000-pound and 500-pound bombs due to concern over the impact they could have in Gaza during the war that began with Hamas’ deadly Oct. 7 cross-border raid.

The administration’s particular concern had been use of such large bombs in Rafah, where over one million Palestinians had taken refuge.

"We’ve been clear that our concern has been on the end-use of the 2,000-lb bombs, particularly for Israel’s Rafah campaign which they have announced they are concluding," a U.S. official said, speaking on the condition of anonymity.

One 2,000-pound bomb can rip through thick concrete and metal, creating a wide blast radius.

Also read: Israel orders civilians to leave Gaza City, strikes UNRWA building

The U.S. official said the 500-pound bombs were put together in the same shipment with the larger ones that were paused and therefore got held up.

"Our main concern had been and remains the potential use of 2,000 lb bombs in Rafah and elsewhere in Gaza ... Because our concern was not about the 500 lb bombs, those are moving forward as part of the usual process," the official added.

The US has notified Israel that it is releasing the 500-pound bombs but keeping the hold on the larger ones, a person familiar with the matter said.

In June, Israeli Prime Minister Benjamin Netanyahu claimed Washington was withholding weapons, and pleaded with U.S. officials to remedy the situation. Biden s aides expressed disappointment and confusion over the Israeli leader s remarks.

Also read: More than two dozen Gazans killed in Israeli strike

During his visit to Washington, Israeli Defense Minister Yoav Gallant said there had been significant progress on the issue of US munitions supply to Israel, adding "obstacles were removed and bottlenecks were addressed."

Despite the pause on one shipment, Israel has continued to receive steady flow of US weaponry.

Reuters reported last month that between the start of Gaza war last October and end-June, the US has transferred at least 14,000 of the MK-84 2,000-pound bombs, 6,500 500-pound bombs, 3,000 Hellfire precision-guided air-to-ground missiles, 1,000 bunker-buster bombs, 2,600 air-dropped small-diameter bombs, and other munitions.

International scrutiny of Israel s military operation in Gaza has intensified as the Palestinian death toll from the war has exceeded 38,000, according to the Gaza health ministry, and has left the coastal enclave in ruins.

The latest bloodshed in the decades-old Israeli-Palestinian conflict began on 7 October when Palestinian Hamas militants attacked southern Israel, killing 1,200 people and took 250 others hostage, according to Israeli tallies.