WASHINGTON >> The United States has told Israel it must take steps in the next month to improve the humanitarian situation in Gaza or face potential restrictions on U.S. military aid, U.S. officials said, in the strongest such warning since Israel’s war with Hamas began a year ago.

U.S. Secretary of State Antony Blinken and Defense Secretary Lloyd Austin wrote to Israeli officials on Sunday demanding concrete measures to address the worsening situation in the Palestinian enclave amid a renewed Israeli offensive in northern Gaza, U.S. officials said on Tuesday.

Failure to do so could impact U.S. policy, said the letter, which was first reported by Israeli News 12.

“We are particularly concerned that recent actions by the Israeli government … are contributing to an accelerated deterioration in the conditions in Gaza,” said a copy of the letter posted by an Axios reporter on X.

The letter cited restrictions Israel was imposing, including those on commercial imports, the denial of most humanitarian movements between northern and southern Gaza, and “burdensome and excessive” restrictions on what goods can enter Gaza.

White House national security spokesperson John Kirby said the letter “was not meant as a threat” but reiterated the urgency of increasing humanitarian assistance in Gaza.

“It appears to us that they (the Israelis) are taking this seriously,” Kirby said of the letter, without elaborating.

An Israeli official in Washington said the letter had been received and was being reviewed. “Israel takes this matter seriously and intends to address the concerns raised in this letter with our American counterparts,” the official said.

The letter is the clearest ultimatum yet to Prime Minister Benjamin Netanyahu’s government since the Gaza conflict began, raising the prospect of a shift in Washington’s support for Israel.

The letter outlined specific steps Israel must take within 30 days, including enabling a minimum of 350 trucks to enter Gaza per day, instituting pauses in fighting to allow aid delivery and rescinding evacuation orders to Palestinian civilians when there is no operational need.

“Failure to demonstrate a sustained commitment to implementing and maintaining these measures may have implications for U.S. policy … and relevant U.S. law,” the letter said.

It cited Section 620i of the Foreign Assistance Act, which prohibits military aid to countries that impede delivery of U.S. humanitarian assistance.

It also cited a National Security Memorandum U.S. President Joe Biden issued in February that requires the State Department to report to Congress on whether it finds credible Israel’s assurances that its use of U.S. weapons does not violate U.S. or international law.

REPEATED WARNINGS

Washington has frequently pressed Israel to improve humanitarian conditions in Gaza since the war with Hamas began with the Palestinian militant group’s Oct. 7, 2023 attacks on southern Israel. The Biden administration has mostly declined to impose restrictions on the billions of dollars of military aid the United States sends to Israel, even after previous warnings over its conduct in the war were not heeded.

Israel says it is following international law in its operations aimed at rooting out Hamas militants hiding in tunnels and among Gaza’s civilian population.

The administration appeared to balance its criticism of Israel’s actions in Gaza with a strong show of military support by announcing on Sunday – the same day as the letter – that it would send U.S. troops and the advanced THAAD anti-missile batteries to Israel.

State Department spokesperson Matthew Miller said Blinken also sent a letter in April demanding from Israel improvements in aid access. Biden also warned in April that U.S. policy would be determined based on Israel’s actions in Gaza.

Miller said Israel at the time made changes that led to 300-400 aid trucks entering Gaza per day but that number had since fallen by more than 50%.

“We very much want to see changes not wait for 30 days, but happen immediately,” Miller said.

CIVILIAN HARM

Israeli forces have expanded operations into northern Gaza amid concerns about access to humanitarian aid throughout the enclave and civilians’ access to food, water and medicine.

Reuters reported earlier this month that food supplies have fallen sharply since Israeli authorities introduced a new customs rule on some humanitarian aid and are separately scaling down deliveries organized by businesses.

The letter also proposed a new channel for the U.S. to “raise and discuss civilian harm incidents” with Israel.

Miller declined to expand on that, but said Israel was not taking sufficient steps to address harm to civilians.

“You have to look no further to understand that than the really horrific results over the weekend,” Miller said.

That was a reference to an Israel missile attack early on Monday that was captured in videos, which could not be independently verified, that appeared to show Palestinians burning alive inside a hospital tent.

The Israeli military said it struck militants operating from a command center inside a hospital compound, accusing Hamas of using civilian facilities such as hospitals for military purposes, which Hamas denies.

Blinken earlier this year concluded that Israel may have violated international humanitarian law using U.S.-supplied weapons and “did not fully cooperate” with efforts to get humanitarian aid into Gaza, but said this did not amount to a breach of U.S law.

Reporting by Humeyra Pamuk, Matt Spetalnick, Simon Lewis, Patricia Zengerle, Phil Stewart, Daphne Psaledakis and Doina Chiacu.