The Biden administration has warned Israel that it will face potential punishment, including a possible halt to US arms transfers, if it does not take immediate action to allow more humanitarian aid into Gaza.

In the letter, written by US Secretary of State Antony Blinken and US Secretary of Defense Lloyd Austin, the Biden administration is urging Benjamin Netanyahu's government to ease humanitarian suffering in the region by lifting restrictions on aid entry within 30 days or face unspecified political "consequences."

The four-page letter, dated October 13, was sent to Yoav Gallant, Israel’s defense minister, and Ron Dermer, the minister of strategic affairs, and came to light after it was shared on social media. State Department spokesman Matthew Miller confirmed Tuesday that the letter was authentic and that it used plain language to highlight the urgency of the moment and the magnitude of Palestinian suffering.

Miller said the US side intended the letter to be a private diplomatic communication, adding that its timing was not influenced by next month's presidential election, which is hotly contested in Michigan, where many Arab American voters have expressed anger at the White House's support for Israel's conduct in the war.

In response to a question from the Jerusalem correspondent about why he wrote it in the form of a letter, rather than using the phone, Miller hinted that the letter contains several specific details that the administration wants to see fulfilled in order to bring aid into Gaza and reduce the suffering of the Palestinians.

In response to a question from the Jerusalem correspondent about what will happen to the besieged Palestinians (400,000) within the 30 days specified in the letter, “they may die of hunger or burn,” as we have seen, Miller said, “The administration expects aid to be delivered immediately, without delay.”

Democratic strategists fear that discontent over Gaza could cost Kamala Harris, the party's vice president and nominee, the state to Donald Trump in the Nov. 5 election.

The letter complains of delays in US-funded aid at crossing points into Gaza, and says aid flows to the war-ravaged territory have dropped by more than 50 percent since Israel promised in March to allow more aid to be delivered.

After a surge in aid following U.S.-Israel contacts in March and April, aid entering the Strip in September fell to its lowest levels, Blinken and Austin wrote, since last October, when Israel launched a massive military offensive in response to a Hamas attack that killed some 1,200 Israelis and took more than 250 hostages.

The letter says the administration is particularly concerned about recent actions by the Israeli government...that are contributing to the accelerating deterioration of conditions in Gaza, and are dealing a severe blow to the downward humanitarian trajectory. “Consistent with its assurances to us, Israel must, beginning now and within 30 days, take ‘a series of specific steps, including allowing the entry of at least 350 trucks of aid per day and imposing humanitarian pauses in Israeli military activity.’”

“Failure to demonstrate a sustained commitment to implementing and maintaining these measures could have implications for U.S. policy under NSM-20 and relevant U.S. law,” the letter adds.

NSM-20 refers to a memorandum issued by the White House National Security Council that allows for “appropriate next steps” if the State Department or Pentagon determines that a country receiving U.S. military assistance is not meeting previous assurances to allow the delivery of humanitarian aid.

The memo states that “such reform could include measures ranging from renewal of assurances to suspension of any further transfers of defense articles or, as appropriate, defense services.”

Congressional Republicans called on the White House to rescind NSM-20, calling it “redundant” and dismissing it as intended to “mollify critics of security assistance to our vital ally Israel.”

Other relevant legislation that could be used is Section 620I of the Foreign Assistance Act and the Leahy Act, which prohibits the U.S. government from providing military assistance or selling weapons to countries that restrict humanitarian assistance or violate human rights.

Miller, the State Department spokesman, declined to elaborate when asked what consequences Israel might face for refusing to meet U.S. demands for increased aid access.

“There are implications under U.S. law that I won’t talk about, largely because we hope Israel will make the changes that the secretary outlined in the letter,” he said. “We’ve seen Israel make changes before, and when it makes changes it can increase humanitarian assistance. We know that can be done.”

He said a previous letter Blinken wrote in April increased humanitarian aid flows. An Israeli official confirmed the latest letter had been received but would not discuss details, the Associated Press reported.

There has been repeated US push to allow increased aid to the besieged enclave to ease humanitarian suffering. The floating dock, announced by Joe Biden in his State of the Union address, was initially hailed as a breakthrough in providing aid but was eventually dismantled after it suffered repeated weather and security problems.

Meanwhile, at least a half-dozen government officials have resigned in protest at U.S. support for the Israeli military operation. Stacey Gilbert said she resigned in protest over an administration report to Congress that falsely stated that Israel had not blocked aid.

The Guardian reported this year that US officials had documented more than a dozen cases of abuse since 2020 but that weapons continued to flow to Israel.

More than 42,000 Palestinians, most of them women and children, have been killed and most buildings in Gaza have been destroyed or badly damaged in a year-long Israeli offensive with the stated aim of eradicating Hamas.

Netanyahu has repeatedly ignored U.S. entreaties to moderate its conduct of the war in Gaza. Israel insists much of the aid has dual-use potential that could help Hamas militants and also says it has been plundered.