Failure to step up aid supplies “may have implications for US policy under NSM-20”, the letter reads, referring to the regulations governing weapons supplies to US allies.

The letter lists “concrete measures” that Israel must take in the next 30 days, such as enabling at least 350 trucks of aid into Gaza every day, as well as opening a fifth border crossing.

The US election, however, falls on Nov 5 – in just 21 days – and the threat to arms supplies will probably be moot if Donald Trump wins.

According to the letter, Israel must “institute adequate humanitarian pauses” to allow for “humanitarian activities”, including vaccinations, deliveries and distribution for at least the next four months.

People in the humanitarian zone of Mawasi in southern Gaza must be allowed to move inland before winter while security for fixed humanitarian sites and people’s movements must be enhanced.

Evacuation orders must be rescinded in the areas where there is no military activity, and Israel must facilitate “rapid implementation of the World Food Programme’s winter and logistics plans to repair roads and install warehouses”.

The number of “vetted drivers” must be increased to 400, essential items from the dual-use restricted list must be removed, and the Jordanian armed forces need to be allowed to enter northern Gaza for aid deliveries.

Forced evacuations from northern to southern Gaza have to stop, the letter states, and humanitarian organisations must have full access to northern Gaza.

Israel has yet to comment on the letter, which was sent to Yoav Gallant, its defence minister.

Netanyahu attack pledge to Biden

It came amid reports that Benjamin Netanyahu has told Joe Biden that Israel will not attack Iran’s oil or nuclear facilities before the US election.

The price of oil fell after The Washington Post reported that Israel’s response would be relatively restrained and focus on Iran’s military bases.

The US president had advised Israel not to strike nuclear or oil plants, fearful of a spike in oil prices that could swing the election against the Democrats.

Israel’s response will be carried out before the US election, two sources told the Post.

One source said the decision by Israel to launch a comparatively moderate attack was made to avoid “political interference in the US elections”.

This decision was among the reasons that Mr Biden decided to deploy the anti-ballistic Thaad battery system and 100 American military personnel to Israel, the report added.

Mr Netanyahu issued a statement on Tuesday, saying that Israel “listens to the opinions of the United States”, but will make its own final decisions “based on our national interests”.

Israel pledged to extract a “heavy price” from Iran after it fired 180 ballistic missiles at military and civilian areas in Israel on Oct 1. It marked the second time in six months that Iran had decided to attack Israel directly with ballistic missiles.