David Cameron says it is “incredibly frustrating” that Israel is not taking steps to allow more aid into Gaza amid a “terrible humanitarian situation”.
The foreign secretary told the BBC on Friday: “We need 500 trucks a day or more going into Gaza. In the last five days, we’ve been averaging 123.”
He called on Israel to open more crossing points to “fix” the problem.
His comments came after the US said it would construct a temporary harbour to ship aid into the Gaza Strip.
The UN says a quarter of Gaza’s population is on the brink of famine and children are starving to death. The US joined other countries at the weekend in dropping aid by plane.
Lord Cameron told BBC Radio 4’s World at One programme that delivery shortages “can be fixed if Israel opens more crossing points, if they allow more UN staff into Gaza to help process the aid and get it round the different bits of Gaza”.
“And they could also do things like full resumption of the water and the electricity that goes into north and south Gaza,” he added.
“We’ve set out these points repeatedly and it’s incredibly frustrating that these things haven’t happened when you think of the terrible humanitarian situation in Gaza.”
Lord Cameron also said on Friday that the UK will join the US and other allies in creating a maritime corridor to deliver aid directly to Gaza.
The UK contribution to the maritime corridor is not expected to involve the deployment of British personnel.
Downing Street said on Friday the UK had been involved in planning and surveying for the pontoon and would now be “working with partners to operationalise our maritime aid corridor from Cyprus”.
But Lord Cameron suggested a temporary harbour would “take months to stand up”. In the meantime, he urged Israel to “promise today” to open its functioning Ashdod Port, to where aid could be shipped from Cyprus and driven into Gaza.
The foreign secretary said a judgement would be made on whether Israel remains compliant with international humanitarian law “in the coming days”.
Asked whether the UK could press Israel on Gaza aid by withholding arms sales, he said: “In terms of export licensing, that depends on the judgement that we make about international humanitarian law and that judgement is undergoing at the moment.
“I’ve set out very clearly in Parliament and elsewhere the processes we have to go through and we’re going through them now.”
Israel denies impeding the entry of aid to Gaza and accuses aid organisations of failing to distribute it.
Aid lorries have been entering the south of Gaza through the Egyptian-controlled Rafah crossing and the Israeli-controlled Kerem Shalom.
But the north, which was the focus of the first phase of the Israeli ground offensive, has been largely cut off from assistance in recent months.
An estimated 300,000 Palestinians are living there with little food or clean water.
Israel’s military launched an air and ground campaign in Gaza after Hamas’s attacks on Israel on 7 October, in which about 1,200 people were killed and 253 others were taken hostage.
More than 30,800 people have been killed in Gaza since then, the territory’s Hamas-run health ministry says.