The UN says bakeries and kitchens have shut down due to limited supplies in the region.
The UN said all its attempts to support the estimated 65,000 to 75,000 people in Beit Hanoun, Beit Lahia and Jabalia this month had been denied or impeded, forcing bakeries and kitchens to shut down.
Earlier this month, a UN-backed assessment said there was a strong likelihood that famine was imminent in areas of northern Gaza.
Hundreds of people have been killed and between 100,000 and 130,000 others have been displaced to Gaza City, where the UN has said essential resources like shelter, water and healthcare are severely limited.
UN agencies had planned 31 missions to the besieged areas of North Gaza governorate between 1 and 18 November, according to the Office for the Co-ordination of Humanitarian Affairs (OCHA).
Twenty-seven were rejected by Israeli authorities and the other four were severely impeded, meaning they were prevented from accomplishing all the work they set out to do.
People individually care, I care, but as a community it is too far away for people be concerned about it.
It is obvious from the hatred protestors are getting everywhere, the haste with which media and the public make the Palestinians the villian are Israeli the victims.