Six aid trucks crossed from Israel directly into northern Gaza on Tuesday as part of a pilot project for ensuring the delivery of supplies into the area, the Israeli army announced.

Aid groups have been warning of the risk of famine in besieged Gaza for weeks, and the United Nations has reported particular difficulty in accessing the territory's north for deliveries of food and other humanitarian supplies.

According to the army, six World Food Programme (WFP) aid trucks "entered the northern Gaza Strip via the '96th' gate on the security fence" on Tuesday.

"This was done as part of a pilot in order to prevent the Hamas terrorist organization from taking over the aid," it added, noting the trucks had been inspected at Kerem Shalom beforehand.

"The pilot's results will be presented to government officials."

Israel has maintained strict control over aid entering the Gaza Strip since the outbreak of its war with Hamas, inspecting shipments at Nitzana and Kerem Shalom before permitting them to enter through the territory's south.

The cumbersome screenings are a major reason current shortages are so glaring, aid workers say, and the shipments sometimes struggle to reach northern Gaza.

Israel blames problems on the Palestinian side for inadequacies in aid delivery.

The United States and other countries have been airdropping supplies into northern Gaza, and an aid ship is en route from Cyprus on a new humanitarian maritime corridor, but aid workers have said stepped-up land deliveries would be much more effective at delivering supplies at scale.

Without specifically mentioning the new overland route, the WFP wrote on X, formerly Twitter, that it had "delivered enough food for 25,000 people to Gaza City early Tuesday in (the) first successful convoy to the north since 20 February".

"With people in northern #Gaza on the brink of famine, we need deliveries every day + we need entry points directly into the north," it said.