Britain’s defence ministry is considering sending troops into Gaza to escort trucks of aid being driven off a giant floating pier built by the US military, a UK defence source has said.

The pier is due to be completed next month in the eastern Mediterranean, and then it will be pushed towards the Gaza shore. But the US president, Joe Biden, has pledged that American forces managing the project will not set foot on land there.

That means someone else must be found to take responsibility for one of the most challenging parts of a politically contentious aid delivery.

There is “consideration” of a UK role inside the British defence ministry, a source said, although the challenges mean it seems unlikely. “It’s not a done deal, and the mood music is probably not.”

The idea emerged “organically” during discussions between the UK and the US about aid deliveries from the pier, the source added.

No proposal has been sent to the prime minister, Rishi Sunak, for consideration, according to the BBC, which first reported a possible UK role. The ministry declined to comment.

Officials in Washington are probably casting around for possible partners willing to take on a mission that will incur huge risks, and carry little upside beyond currying favour in Washington.

Whoever drives the trucks off the floating pier will be going into an active combat zone where more than 200 humanitarian workers have been killed.

The Israeli bombing of an aid convoy run by World Central Kitchen on 1 April, in which seven international aid workers died, heightened security concerns around any independent distribution effort.

The level of desperation and hunger in northern Gaza means there is also a risk from huge crowds trying to reach trucks carrying supplies, although the US plan envisages aid being unloaded in a secure area before it is transferred to trucks driven by Palestinians for delivery across Gaza.

In late February at least 112 people were killed and more than 700 injured in a “massacre” when Israeli forces opened fire on a crowd gathered around aid trucks. Israel said people died in a crush or were run over by aid lorries, although it admitted its troops had opened fire.

The US pier is designed to stave off famine in Gaza’s north, with the US saying it is designed to supplement, not replace, land deliveries. The ambition is for the new sea route to allow 90 trucks a day of supplies in to Gaza, rising to 150.

But there are growing concerns in the humanitarian community about how useful it will be. When the US uses innovative military technology to get aid into disaster zones, it is usually because access is blocked by geography or hostile actors.

In Gaza, the Israeli authorities have refused to open more land routes – which are cheaper and quicker – to allow aid in, despite repeated requests from the US.

Both the US and Israel have said they are aiming for aid shipments to reach 500 trucks of aid a day, roughly matching prewar levels – although the territory had a functioning economy and agricultural sector then, so the need was far lower.

The average shipped over the last month was less than half that, according to UN figures, so even with the floating pier at full capacity, Gaza will need more access by land.

There are also fears that Israel is trying to exploit the deliveries to sideline Unrwa, the UN agency for Palestinian refugees, which is the main provider of food aid in the territory. The US announced last week that the World Food Programme (WFP) will help distribute aid inside Gaza after it arrives at the pier.