The US Central Command (CENTCOM) said on Tuesday more than 569 metric tons of humanitarian assistance has been delivered so far across a temporary floating pier to Gaza, but not all the aid has reached warehouses.
Aid deliveries began arriving at a US-built pier on Friday as Israel comes under growing global pressure to allow more supplies into the besieged coastal enclave.
The UN said that 10 truckloads of food aid - transported from the pier site by UN contractors - were received on Friday at a World Food Programme warehouse in Deir El Balah in Gaza.
But on Saturday, only five truckloads made it to the warehouse after 11 others were cleaned out by Palestinians during the journey through an area that a UN official, speaking on condition of anonymity, said has been hard to access with humanitarian aid.
The UN did not receive any aid from the pier on Sunday or Monday.