The head of the UN's emergency food relief agency on Sunday issued an urgent appeal from the Rafah border crossing for safe, expanded humanitarian access to Gaza as critical food supplies in the ravaged enclave reach dangerously low levels.

'Right now, parents in Gaza do not know whether they can feed their children today and whether they will even survive to see tomorrow. The suffering just meters away is unfathomable standing on this side of the border,' said Cindy McCain, Executive Director of the UN World Food Programme (WFP).