Israel said it was letting trucks of baby food into the Gaza Strip on Monday, the first aid to be admitted since the Israeli government announced the partial lifting of a two-month blockade.

Israel, pressing a newly expanded military offensive across the Gaza Strip, has faced mounting pressure, including from key backer the United States, to end the aid blockade it imposed on March 2.

"Today, Israel is facilitating the entry of trucks with baby food into Gaza," foreign ministry director general Eden Bar Tal told reporters on Monday, adding that "in the coming days, Israel will facilitate the entry of dozens of aid trucks."

Asked how many trucks had already entered Gaza, foreign ministry spokesman Oren Marmorstein told journalists that "we need to check the exact number."

He added that "the idea is to have some significant numbers coming in the upcoming days."

UN agencies have warned of critical shortages of food, clean water, fuel and medicines in the besieged territory.

World Health Organisation chief Tedros Adhanom Ghebreyesus said on Monday that the vast majority of Gazans "are starving" while "tonnes of food is blocked at the border, just minutes away." (AFP)