U.S. Secretary of State Antony Blinken and Defense Secretary Lloyd Austin wrote a letter to Israeli Prime Minister Benjamin Netanyahu’s government on October 13, giving Israel 30 days to allow at least 350 humanitarian aid trucks per day into Gaza, open a fifth crossing into the enclave, and ensure access to northern Gaza for aid groups, among other specific steps outlined in the letter.

Noncompliance would violate National Security Memorandum 20, which President Joe Biden issued in February to demand credible assurances from Israel that it was acting according to international law, and Section 620I of the Foreign Assistance Act, which prohibits the U.S. from providing military aid to countries that are blocking U.S. humanitarian aid.

Louise Wateridge, a senior emergency officer for the U.N. Relief and Works Agency for Palestine Refugees in the Near East (UNRWA), said Tuesday that the Biden administration’s warning 30 days ago did not improve conditions in Gaza, with aid entering the enclave “at its lowest level in months.”