White House officials say the assurance was made in a call between President Joe Biden and Prime Minister Benjamin Netanyahu.
Yesterday an aid convoy of 17 trucks of supplies entered the enclave - following an earlier delivery of 20 lorries.
Meanwhile Unicef says the amount of aid getting through to Gaza is not enough for the 2.3 million people who need humanitarian assistance.
It says 17 more humanitarian aid trucks entered the region yesterday, containing water, food and tents.
Its Executive Director, Peter Power says these trucks brought in very little in supplies.
'The UN's humanitarian coordination agency estimated that only 4 per cent of the amount of supplies that are necessary came in through those trucks so we need a massive scaling up of the access - we're talking about hundreds of trucks every day to bring in the amount of humanitarian assistance that's required.'
