Joe Biden has appealed to Israel not to be “consumed” by rage in its response to the attack by Hamas, as the US president pledged stalwart support for Israel for its self-defence and the Israeli prime minister Benjamin Netanyahu promised to allow aid into Gaza via Egypt. Speaking in Tel Aviv towards the end of his one-day visit to the region, which did not include any meetings with leaders from the Arab world, Biden compared Israel’s predicament after the massacre of more than 1,300 of its citizens to the US’s crisis 22 years ago after the 9/11 attacks. His country had “sought and got justice”, but also “made mistakes”, he said. Following hours of talks with Netanyahu and his war cabinet, Biden said Israel had agreed to allow the opening of the Egypt-Gaza border to deliveries of desperately needed food, water and medical supplies after an 11-day total blockade on condition that the humanitarian assistance was not diverted by Hamas for its own use. “The Palestinian people are suffering greatly as well, and we mourn the loss of innocent Palestinian lives like the entire world,” the US president said. “The people of Gaza need food, water, medicine and shelter.” He vowed that the US would continue to provide for Israel’s security needs, and supported Israel’s assessment that a devastating blast at a Gaza City hospital on Tuesday night was not the result of an Israeli airstrike, but of “an errant rocket fired by a terrorist group in Gaza”. After his departure, the Israeli prime minister’s office said in a statement: “In light of President Biden’s demand, Israel would not foil the supply of humanitarian aid via Egypt.” The statement noted that aid to civilians in the southern Gaza Strip would be allowed “so long as these supplies do not reach Hamas”, which has political control over the enclave. Later on Wednesday, Biden told reporters he had spoken to the Egyptian president, Abdel Fatah al-Sisi, who had agreed to reopen the Rafah crossing to allow 20 trucks with humanitarian aid supplies to enter Gaza. US officials are believed to have tried to convince their Israeli counterparts in meetings during the presidential visit that a scorched-earth response in Gaza would trigger a humanitarian catastrophe, a loss of global support for Israel and perhaps a wider war, without eradicating Hamas. The UN and other aid agencies have warned that Gaza’s entrapped population of 2.3 million people is in imminent danger of death by dehydration, hunger, disease and injuries from bombardment. The ActionAid agency said that 70% of the more than 3,000 Palestinians killed in the past 10 days were women and children. Humanitarian organisations have stockpiled life-saving supplies on the Egyptian side of the border, waiting for the crossing at Rafah to open. Earlier assurances this week that agreement had been reached proved unfounded, and Biden’s remarks suggested that Israeli security concerns had been the greatest obstacle. In emotional remarks to reporters, Biden made clear that he understood the grief and agony of the victims’ families from the 7 October cross-border assault by Hamas, when 199 Israelis were also taken hostage. “Justice must be done,” Biden said. “But I caution that, while you feel that rage, don’t be consumed by it. After 9/11, we were enraged in the United States. While we sought justice and got justice, we also made mistakes.” While Biden was in Tel Aviv, the US gave diplomatic support to Israel at the UN, vetoing a security council resolution that would have called for a humanitarian ceasefire to allow for aid deliveries and would have urged Israel to rescind its order to the population of northern Gaza to move to the southern half of the enclave. In Tel Aviv, Biden accompanied his pledge of US support with words of advice. In a clear message to Netanyahu’s government, he said leadership in times of war required clear thinking and tough decisions. “There’s always cost,” he said. “It requires being deliberate, it requires asking very hard questions, it requires clarity about the objectives and an honest assessment about whether the path you’re on will achieve those objectives. “Today I asked the Israeli cabinet … to agree to the delivery of life-saving humanitarian assistance to civilians in Gaza. Based on the understanding that there will be inspections, that the aid should go to civilians, not to Hamas, Israel agreed humanitarian assistance can begin to move from Egypt to Gaza,” Biden said. Trucks would start crossing the border “as soon as possible”, he said. But he added: “Let me be clear: if Hamas diverts or steals the assistance, they will have demonstrated once again that they have no concern for the welfare of the Palestinian people, and as a practical matter it will stop the international community from being able to provide this aid.” Biden expressed grief for the hundreds of Palestinians thought to have died in the explosion at al-Ahli Arab hospital in Gaza City on Tuesday night, but he said the US agreed with Israel on the cause. “Based on the information we have seen to date, it appears as a result of an errant rocket fired by a terrorist group in Gaza,” he said. The Israel Defence Forces have said the cause was a rocket fired by Palestinian Islamic Jihad, while Hamas says the blast was caused by an Israeli airstrike. Lebanon’s Iran-backed Hezbollah movement had called for a “day of rage” on Wednesday, and there were protests in the Israeli-occupied West Bank, Lebanon, Jordan, Libya, Yemen, Tunisia, Turkey, Morocco and Iran. The bombing of the hospital and its heavy death toll led to the cancellation of what was supposed to be the second leg of Biden’s Middle East peace mission – a meeting in Amman with Jordan’s King Abdullah, the Egyptian president, Abdel Fatah al-Sisi, and the head of the Palestinian Authority in the West Bank, Mahmoud Abbas. The White House said that the president would speak to the Arab leaders by phone from Air Force One on his trip home. The cancellation of the Amman meeting, after Abbas returned to the West Bank and declared three days of mourning, combined with Biden’s emotional expressions of support for Israel, fuelled accusations that the US president was not acting as an honest broker in the conflict. The 57-member Organisation of Islamic Cooperation issued a statement deploring “the international positions that back the brutal aggression against the Palestinian people, and grant Israel impunity”. The US was also criticised by human rights groups for its veto at the UN security council. “Once again, the US cynically used their veto to prevent the UN security council from acting on Israel and Palestine at a time of unprecedented carnage,” Louis Charbonneau, the UN director at Human Rights Watch, said. “In so doing, they blocked the very demands they so often insist upon in other contexts: all parties to comply with international humanitarian law and ensure that vital humanitarian aid and essential services reach people in need.”