Children sit amid the rubble of destroyed buildings in Rafah on the southern Gaza Strip on December 29, 2023. (AFP)

The United Nations has expressed frustration at how life-saving aid is being hampered from entering the Gaza Strip as the dire humanitarian crisis worsens with no end in sight to Israel’s weeks of constant siege and bombardment of the populated coastal territory.

UN humanitarian chief Martin Griffiths called out the impossible situation facing people in Gaza and those trying to help them, saying that aid convoys are constantly coming under fire in the territory.

You think getting aid into Gaza is easy? Think again, Griffiths said on Friday in a post on X. This is an impossible situation ... The fighting must stop.

He made the remarks after Israeli forces fired on an aid convoy as it returned from northern Gaza along a route designated Safe by the military.

Thomas White, director of UNRWA affairs in Gaza said, Our international convoy leader and his team were not injured but one vehicle sustained damage - aid workers should never be a target.

The persistent difficulty in getting humanitarian relief into the besieged Palestinian territory comes as a UN-backed report said last week that the entire 2.3 million population of Gaza is facing crisis levels of hunger, with 576,600 people at catastrophic - or starvation - levels.

Israel imposed a total siege on the coastal enclave since it launched its relentless air and ground offensive on Palestinians on Oct.7. The blockade has deprived the population of Gaza of food and water.

The United Nations Security Council passed a resolution last week to boost humanitarian assistance to Gaza with Secretary-General Antonio Guterres calling for an immediate humanitarian ceasefire.

The UN chief said then that a humanitarian ceasefire is the only way to begin to meet the desperate needs of people in Gaza and end their ongoing nightmare.

He also said Israel is creating massive obstacles for entry of aid into Gaza. The real problem is that the way Israel is conducting this offensive is creating massive obstacles to the distribution of humanitarian aid inside Gaza.