Smoke billows over Khan Yunis during Israeli bombardment from Rafah in the southern Gaza Strip. File/AFP

Israel kept up its deadly bombardment of war-torn Gaza as Washington vetoed a UN Security Council resolution that called for a ceasefire in the Palestinian territory.

Global powers trying to navigate a way out of the spiralling crisis have so far come up short, and mediation efforts have so far failed to secure a truce to halt the fighting.

Adding to Gaza's woes, the UN's food agency said Tuesday that it had to stop desperately-needed deliveries to the north of the territory after facing "complete chaos and violence" there — a decision condemned by Hamas.

The World Food Programme had only just resumed deliveries Sunday but said its convoy was met with gunfire, violence and looting, while a truck driver was beaten.

"We are shocked about this decision by the World Food Programme to suspend the delivery of food aid in northern Gaza, which means a death sentence and death for three-quarters of a million people," the Hamas government media office said Tuesday night.

US Ambassador to the UN Linda Thomas-Greenfield casts a veto vote during a UN Security Council meeting. AFP

Calling on the agency to "immediately reverse its disastrous decision", it said "we hold the United Nations and the international community responsible".

Since the start of the war between Israel and Hamas, Gaza has been plunged into a food crisis, with outside aid severely restricted.

The UN has repeatedly sounded the alarm over the dire humanitarian situation in Gaza, warning that food shortages could lead to an "explosion" of preventable child deaths.

More than four months of relentless fighting have flattened much of the coastal territory, pushing 2.2 million people to the brink of famine and displacing three-quarters of the population, according to UN estimates.

"We can't take it anymore. We do not have flour, we don't even know where to go in this cold weather," said Ahmad, a resident of Gaza city, where streets are strewn with rubble from destroyed buildings and garbage.

"We demand a ceasefire. We want to live," he said.

Agence France-Presse