The top U.N. humanitarian official is accusing Israel of blocking the delivery of desperately needed aid to Gaza, and the U.S. ambassador is demanding that its government step up efforts to tackle the Palestinian territory’s ”intolerable and catastrophic humanitarian crisis.

Israel transported 50 trucks of humanitarian aid from Jordan to Gaza on Wednesday, October 16, after the US warned the country that they would curb missile supplies to Israel if they didn’t let more aid in.