Britain, France and Germany on Friday urged an end to Gaza's"humanitarian catastrophe" as the UN food agency warned almost a third of people in the war-ravaged Palestinian territory were not eating for days.

Alarm has been mounting about the deepening crisis in Gaza, with aid groups saying that"mass starvation" is spreading after more than 21 months of conflict.

Gaza's civil defence agency added that Israeli military operations killed at least 28 people on Friday across the Palestinian territory.

In a joint statement, the leaders of the three European powers urged Israel"to immediately lift restrictions on the flow of aid and urgently allow the UN" and NGOs to "take action against starvation".

"The most basic needs of the civilian population, including access to water and food, must be met without any further delay," they said.

"Withholding essential humanitarian assistance to the civilian population is unacceptable. Israel must uphold its obligations under international humanitarian law."

UN Secretary-General Antonio Guterres on Friday also slammed the international community for turning a blind eye to widespread starvation in the Gaza Strip, calling it a"moral crisis that challenges the global conscience."

"I cannot explain the level of indifference and inaction we see by too many in the international community -- the lack of compassion, the lack of truth, the lack of humanity," Guterres told Amnesty International's global assembly via video link.

"This is not just a humanitarian crisis. It is a moral crisis that challenges the global conscience. We will continue to speak out at every opportunity."

Guterres said while he had repeatedly condemned the October 7, 2023 attack by Hamas on southern Israel, which triggered the war in the Palestinian territory,"nothing can justify the explosion of death and destruction since".

"The scale and scope is beyond anything we have seen in recent times," he said.

"Children speak of wanting to go to heaven, because at least, they say, there is food there. We hold video calls with our own humanitarians who are starving before our eyes... But words don't feed hungry children."

He added that the United Nations was ready to "dramatically scale up humanitarian operations" in Gaza should Israel and Hamas reach a ceasefire deal.

Italian Foreign Minister Antonio Tajani added his voice to the criticism, saying his country cannot accept"carnage and famine" in Gaza.

Concern is growing in particular about surging numbers of malnourished children. Doctors Without Borders (MSF) says that a quarter of the young children and pregnant or breastfeeding mothers it had screened at its clinics last week were malnourished.

Warning that the crisis had reached"new and astonishing levels of desperation", the United Nations food agency said:"Nearly one person in three is not eating for days."

"Malnutrition is surging with 90,000 women and children in urgent need of treatment," said the Rome-based World Food Programme.

"Food aid is the only way for people to access any food as food prices are through the roof... People are dying from lack of humanitarian assistance."

Israel has rejected accusations it is responsible for the deepening crisis in Gaza, which the World Health Organization has called"man-made".

Israel placed the Gaza Strip under an aid blockade in March, which it only partially eased two months later while sidelining the longstanding UN-led distribution system.

Calls for ceasefire

In their joint statement, Germany, France and Britain also stressed that"the time has come to end the war in Gaza.

"We urge all parties to bring an end to the conflict by reaching an immediate ceasefire."

In a separate statement Friday, British Prime Minister Keir Starmer signalled that London will not imminently recognise a Palestinian state, after French President Emmanuel Macron said a day earlier that his country intended to do so in September.

Starmer said that he was"unequivocal" Britain should eventually recognise a Palestinian state, but that this step"must be part of a wider plan which ultimately results in a two-state solution".

He is facing mounting pressure however, with more than 220 British MPs, including dozens from the ruling Labour party, demanding that his government formally recognise a Palestinian state.

Britain's position is similar to that of Germany, which said it regarded the recognition of a Palestinian state as"one of the final steps on the path to achieving a two-state solution".

Palestinian militant group Hamas triggered the conflict with its October 7, 2023 attack in Israel.

The Hamas attack resulted in the deaths of 1,219 people, most of them civilians, according to an AFP tally based on official figures.

Israel's military campaign in Gaza has so far killed 59,676 Palestinians, mostly civilians, according to the health ministry in the Hamas-run territory.

Of the 251 hostages taken during the attack, 49 are still being held in Gaza, including 27 the Israeli military says are dead.