The 12-person crew, which includes Swedish climate activist Greta Thunberg, Irish actor Liam Cunningham and Franco-Palestinian MEP Rima Hassan, set sail on the Madleen from the port of Catania on Sunday, carrying barrels of relief supplies that the group called “limited amounts, though symbolic”.

A U.S.- and Israeli-backed private organization is overhauling the aid distribution system in Gaza. The United Nations says it undermines humanitarian principles.

The embattled Israeli-backed aid group that began operating in Gaza earlier this week is not screening Palestinians at aid distribution sites, despite Israeli officials saying that additional security measures were a core reason for the creation of the new program.

The United Nations says food being distributed by a new Israeli-backed system is “less than a drop in the ocean.”

The situation in Gaza is the worst since the war between Israel and Hamas militants began 19-months ago, the United Nations said on Friday, despite a resumption of limited aid deliveries in the Palestinian enclave where famine looms.

The United Nations, the global symbol of multilateral cooperation and humanitarian action, is facing an unprecedented financial reckoning.

Spokesperson Jens Laerke said only 600 of 900 aid trucks had been authorised to get to Israel's border with Gaza.