"It's something that we've been warning about since early April, and that is what is so tragic," John Ging, head of UNRWA in the Gaza Strip, told Al Jazeera.
"Now we're at a standstill - we just don't have the fuel to operate the trucks.
"We have the food, and we certainly have hundreds of thousands of desperate people who need it. But this is the situation tonight."
"The key condition for this ceasefire is that Israel should re-open all the crossings ... to lift the embargo on the Palestinian people"
Ghazi Hamad, Hamas spokesman