The Norwegian Refugee Council told Reuters on Tuesday its aid stocks are completely depleted in Gaza, with some of its staff now starving, and the organisation accused Israel of paralysing its work.
"Our last tent, our last food parcel, our last relief items have been distributed. There is nothing left," Jan Egeland, the secretary general of the council told Reuters in an interview via video link from Oslo.
The council's comments echo those made earlier on Tuesday by the head of the Palestinian refugee agency, who said UNRWA's staff were fainting on the job from hunger and exhaustion.
The NRC says that for the last 145 days, it has not been able to get hundreds of truckloads of tents, water, sanitation, food and education materials into Gaza.
COGAT, the Israeli military aid coordination agency, and Israeli authorities did not immediately respond to a request for comment. It has denied accusations that it is preventing aid from reaching Gaza, and has accused Palestinian group Hamas of stealing food, which Hamas denies.
"Hundreds of truckloads have been sitting in warehouses or in Egypt or elsewhere, and costing our Western European donors a lot of money, but they are blocked from coming in… That's why we are so angry. Because our job is to help," Egeland said.
"Israel is not yielding. They just want to paralyse our work," he added.
The NRC has 64 Palestinian and two international staff on the ground in Gaza. On Sunday the NRC had to move 33 of its staff out of Deir al-Balah following Israeli evacuation warnings.
The NRC said its supplies of safe drinking water are also running out, due to dwindling supplies of fuel to run desalination plants. The water has reached 100,000 people in central and northern parts of Gaza in recent weeks
An Israeli official told Reuters there is about a half a million litres of fuel that the U.N. has been given approval to bring in.
The official also said that there are about 700 trucks of unpacked aid on the Gaza side of the Kerem Shalom crossing which have not been distributed.