Médecins Sans Frontières (MSF) says the air drops "might help" but notes that the "most vulnerable" in Gaza would still struggle to access essential supplies.

United Nations aid chief Tom Fletcher has demanded that Israel provide evidence for its accusations that staff with the U.N. Office for the Coordination of Humanitarian Affairs were affiliated with Palestinian militants Hamas,

Israel has long restricted or completely blocked aid to Gaza on the argument that Hamas steals it to use as a weapon of control over the population.

"The humanitarian catastrophe that we are witnessing in Gaza must end now," a joint statement from the three countries reads.

Plus: Hundreds of people have been killed in recent weeks trying to reach food, mostly in mass shootings by Israeli soldiers.

Gazans are in desperate need of essentials after more than 21 months of war, but efforts to get aid into the Palestinian territory - and to its hungry residents - face major obstacles.

Israel said on Tuesday there were 950 trucks' worth of aid waiting in Gaza - but the agencies accuse Israel of blocking access to it.