The Biden administration has warned Israel that it could face penalties, including a possible halt to U.S. arms transfers, if it does not take immediate action to allow more humanitarian aid into the Gaza Strip.

A letter co-authored by Antony Blinken, the U.S. secretary of state, and Lloyd Austin, the defense secretary, calls on Benjamin Netanyahu’s government to ease humanitarian suffering in the territory by lifting restrictions on the entry of aid within June 30 days, otherwise there will be unspecified political “effects”. “.

The four-page letter, dated Oct. 13, was sent to Yoav Gallant, Israel’s defense minister, and Ron Dermer, strategic affairs minister, and came to light after it was posted on social media by Barak Ravid, an Israeli journalist who works for was published by Axios after it was apparently leaked.

Its authenticity was confirmed by a State Department spokesman, Matthew Miller, at a news conference on Tuesday.

Humanitarian groups have repeatedly called for increased deliveries of food and medicine to Gaza, but aid deliveries to the embattled territory are currently at their lowest level in months, the United Nations said last week.

An Israeli official in Washington told Reuters that Israel was reviewing the letter.

“Israel takes this matter seriously and intends to discuss the concerns raised in this letter with our American counterparts,” the official said.

Miller said the U.S. side intended the letter to be a private diplomatic communication and said its timing was not influenced by next month’s presidential election, which features tough competition in the battleground state of Michigan with many Arab-Americans. American voters expressed anger over the White House’s support for Israel’s war effort.

Democratic strategists fear that discontent with Gaza could lead to Kamala Harris, the vice president and party nominee, losing the state to Donald Trump in the November 5 election.

The letter complains about delays in U.S.-funded aid at Gaza border crossings and says the flow of aid to the war-torn territory has fallen by more than 50% since Israel promised to allow more deliveries last March .

“We are particularly concerned that the Israeli government’s recent actions… are contributing to an accelerated deterioration of conditions in Gaza,” it said.

White House national security spokesman John Kirby said the letter was not intended as a threat but was “simply intended to reiterate the urgency that we feel and the seriousness with which we feel the need to increase, a dramatic increase in humanitarian aid”.

After a surge in aid following communications between the U.S. and Israel in March and April, the amount of aid entering the Strip fell in September to its lowest level since last October, when Israel launched a massive military offensive in retaliation, Blinken and Austin wrote Hamas attack that killed about 1,200 Israelis and took more than 250 hostage.

“In order to reverse the downward trend in humanitarian assistance and in line with its assurances to us, Israel must take a number of specific steps starting immediately and within 30 days,” including allowing at least 350 aid trucks daily and introducing humanitarian breaks for the Israeli military Activity.

The letter continues: “Failure to demonstrate sustained commitment to implementing and sustaining these measures may impact U.S. policy under NSM-20 and relevant U.S. law.”

NSM-20 refers to a memorandum issued by the White House National Security Council that provides “appropriate next steps” if, in the opinion of the State Department or the Pentagon, a country receiving U.S. military assistance fails to meet prior assurances to allow the delivery met humanitarian aid.

“Such remedial action could include measures ranging from refreshing assurances to suspending further deliveries of defense articles or defense services, as appropriate,” the memorandum said.

Republicans in Congress have called on the White House to revoke NSM-20. They called it “superfluous” and dismissed it as aimed at “appeasing critics of security assistance to our vital ally Israel.”

Other relevant laws that could be invoked include Section 620I of the Foreign Assistance Act and the Leahy Act, which prohibit 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 if it refuses to comply with American demands for greater access to aid.

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

Miller also said that Blinken had seen footage that showed at least one Palestinian being burned alive after an Israeli attack set fire to tents outside a hospital in Gaza.

“We have all seen this video and we all know that it is terrible to see people being burned. We have expressed our serious concerns about this matter directly to the Israeli government.”

The U.S. has repeatedly urged it to allow more aid to the Gaza Strip, but Netanyahu has often ignored such requests to moderate his warfare in Gaza.

Last week, UN spokesman Stéphane Dujarric said the three hospitals still operating in northern Gaza were facing “significant shortages” of fuel, medicine and blood, while food supplies were running low.

Israeli authorities have supported only one of 54 U.N. attempts to bring aid to northern Gaza this month, Dujarric said. 85 percent of applications were rejected, the rest were prevented or canceled for logistical or security reasons.

Israel insists that much of the aid has dual-use that could help Hamas militants and also says there has been looting.

More than 42,000 Palestinians have been killed and most buildings in Gaza destroyed or severely damaged in Israel’s year-long offensive with the stated aim of rooting out Hamas.

The Pentagon described the letter as “private correspondence” and declined to discuss it in detail.