The Biden administration warned Israel this week that Washington could suspend military assistance if humanitarian aid flows in Gaza are not increased within a month.

Some of the sharpest criticism about a lack of sufficient assistance in the enclave came from Israel’s allies, including the United States.

The first aid in two weeks was allowed into northern Gaza following the letter, but the UN's acting humanitarian chief Joyce Msuya described it as a “trickle”. In the letter sent on Sunday, the US expressed deep concern at the humanitarian situation and said Israeli actions had contributed to it.

The top U_N_ humanitarian official is accusing Israel of blocking the delivery of desperately needed aid to Gaza, and the U_S_ ambassador is demanding that its government step up efforts to tackle the Palestinian territory’s ”intolerable and catastrophic humanitarian crisis.

The United States has warned Israel that it must take "concrete measures" to improve a worsening humanitarian crisis in Gaza within 30 days or risk losing military assistance provided by Washington.

The US has written to Israel, giving it 30 days to boost humanitarian aid access in Gaza or risk having some US military assistance cut off. The letter, sent on Sunday, amounts to the strongest known written warning from the US to its ally and comes amid a new Israeli offensive in northern Gaza that has reportedly caused a large number of civilian casualties.