Aid organisations said Thursday that a full ceasefire is needed between Israel and Hamas if they are to bring meaningful help to the civilian population in Gaza.
About 10 non-governmental organisations told reporters on the sidelines of a humanitarian summit hosted by France that a simple pause in the fighting would not alleviate what they called a humanitarian "catastrophe".
Their appeal came as US President Joe Biden said that there was "no possibility" of a ceasefire, although Israel had agreed to daily four-hour pauses in fighting.
Several western governments have called for a "humanitarian pause" in Israel's offensive, but not for an immediate ceasefire.
Israel has been battering the Gaza Strip relentlessly since the October 7 attacks by Hamas that Israel says left 1,400 dead, mainly civilians.
More than 10,800 people, have died in Israel's air and ground offensive, according to Gaza's Hamas-run health ministry.
"We don't know what a humanitarian pause means concretely," Isabelle Dufourny, president of the Medecins sans Frontieres NGO, told a joint news conference.
Unless safe areas were created on the battlefield "it's impossible to work", she said.
"Hospital staff are dealing with massive arrivals of wounded people, are working in horrible hygiene conditions, can't rest and are under constant stress," she said.
"Our colleagues tell us: we cannot wait a minute more. End these bombardments, lift this siege," said Jan Egeland, Secretary General of the Norwegian refugee council.
"It's heartbreaking to see that it continues."
Oxfam France director Cecile Duflot said staff were reporting "the worst, the most tragic situation that they have ever seen" in Gaza.
"Our health carers are exhausted, trying to survive" said Jean-Francois Corty, vice president of the Medecins du Monde NGO.
The aid organisations also expressed frustration at being unable to transport crucial aid to the 2.4 million people living in Gaza, one of the world's most densely populated territories.
They said people in Gaza were getting only one litre or water per person per day, compared to a need of 10 litres. About 500 aid trucks have been allowed into the territory from Egypt over the past month, a number that had been the daily average before the war.
"There is something obscene about aid being available, and so difficult to access," Corty said.
International organisations have suffered heavy losses in the war.
Around 100 staff at UNRWA, the United Nations's aid body for Palestinian refugees, have died, including teachers, doctors and nurses, said Philippe Lazzarini, its commissioner-general.