A new report by the International Committee of the Red Cross has described the 1.5m Palestinians living in Gaza as people trapped in rising poverty, and unable to rebuild their lives.
The international charity said large numbers of children were severely malnourished, and that basic medicines were in short supply.
It said thousands of people whose homes were destroyed during Israel's 22-day military operation at the beginning of the year were still without shelter.
The report added that the current situation was directly linked to the continuing Israeli blockade of the crossing points into Gaza.
Read the ICRC report
Meanwhile, a UN human rights panel has begun hearing testimony as part of its investigation into alleged war crimes by Israel and Hamas during the Gaza war.
According to human rights groups, more than 1,400 Palestinians and 13 Israelis were killed during the fighting.
The public hearings are being held in Gaza, and are chaired by the South African Jewish prosecutor, Judge Richard Goldstone.
The panel will hold similar hearings in Geneva next month, to which Israeli witnesses and victims are invited, because the panel has been barred from entering Israel.