An intense US-led diplomatic effort failed on Monday to ease the plight of 2 million Palestinians trapped under bombardment in Gaza, with supplies of water, food and medicine all running out, raising the prospect of a humanitarian disaster. The US secretary of state, Antony Blinken, arrived back in Israel after a tour of the five Gulf Arab states and Egypt as part of an ongoing but faltering diplomatic mission. US media reported that Joe Biden was considering a trip as an already dire situation drastically deteriorated. Trucks carrying badly needed supplies have waited for days at Egypt’s border crossing with Gaza but repeated Israeli strikes and a diplomatic stalemate with Cairo have meant they have been unable to enter. An Israeli airstrike hit the border crossing again on Monday evening, a BBC journalist in Gaza reported, the fourth time the area has been bombed since the war began. Residents of the strip, which is ruled by Hamas, said strikes overnight between Sunday and Monday were the heaviest yet as the conflict entered its 10th day. According to an aid official, a few UN lorries carrying oil were allowed into Gaza from Egypt on Monday morning but the crossing remained closed to most humanitarian deliveries. “No food, nothing of that sort, made it through,” an aid source said. “Nobody is able to get anything close to that border.” Egyptian security services had earlier assured aid agencies and journalists that an agreement had been reached for the Rafah crossing to be opened at 9am on Monday. But in response, the office of the Israeli prime minister, Benjamin Netanyahu, issued a one-line statement saying: “There is no ceasefire.” Thousands of patients’ lives in Gaza are at risk, UN officials said, and civilians – Palestinians and foreigners – wait helplessly in Gaza with no means of escape. Blinken’s team had been trying to negotiate safe passage out through the Rafah crossing for an estimated 500 Palestinian-Americans trapped inside. “The gate is closed. They didn’t let anyone through,” said a Palestinian woman who tried to cross on Monday. “We came at 9am. It is now almost 1.15pm and it didn’t even open for a second.” Many others were waiting for a phone call saying that the crossing was open. Gaza is running out of the basics for sustaining life in the face of a total Israel blockade and bombing campaign in reprisal for a Hamas attack last week that killed more than 1,300 Israelis, mostly civilians. The UN agency for Palestinian refugees, UNRWA, has said a million people have been internally displaced since the Hamas incursion, and the Palestinian health ministry said 2,329 Palestinians had been killed in Gaza. Palestinians in Gaza have increasingly been surviving ​by drinking dirty, salty water.​ Israel has said it had resumed pumping some water to an area in the south of the ​strip but it was not clear how much was getting in. Hamas continued to fire rockets on Monday, with attacks reported on Tel Aviv and other Israeli cities. In the afternoon, the Israeli parliament in Jerusalem, the Knesset, was forced to break from an active session as lawmakers rushed to shelters while bomb sirens blared. As the war in southern Israel raged, to the north the Israeli government began evacuating residents from 28 villages within 2km (1.2 miles) of Lebanon, the military said on Monday. The move followed exchanges of fire with the Lebanese Hezbollah militant group over the past few days, including Hezbollah targeting five Israeli positions on Monday. Blinken’s regional diplomatic effort has so far failed to achieve its aims of establishing safe havens for civilians in Gaza and to open corridors for humanitarian supplies. However, he said he had heard from his tour “a shared view, that we have to do everything possible to make sure this doesn’t spread to other places; a shared view to safeguard innocent lives; a shared view to get assistance to Palestinians in Gaza who need it, and we’re working very much on that”. He met Netanyahu soon after landing and also talked by phone to the Turkish foreign minister, Hakan Fidan. Turkey’s state media reported that the Turkish president, Recep Tayyip Erdoğan, had spoken to his Iranian counterpart, Ebrahim Raisi, and said Ankara was making “intense efforts” to deliver humanitarian aid to Gaza, and that “steps that increase tension should be avoided”. As Israel massed troops and armour around Gaza’s borders in preparation for a ground invasion, Biden has said it would be a “big mistake” for Israel to try to reoccupy the territory once more with ground troops, 18 years after withdrawing its forces. “What happened in Gaza, in my view, is Hamas and the extreme elements of Hamas don’t represent all the Palestinian people,” Biden said in an interview with the CBS news programme 60 Minutes. He said he believed Hamas should be eliminated entirely “but there needs to be a Palestinian authority. There needs to be a path to a Palestinian state”. On Monday, Biden cancelled a scheduled trip to Colorado to hold national security meetings about the Gaza crisis instead, amid reports he could visit Israel in the coming days. John Kirby, a spokesperson for the US national security council, confirmed that Netanyahu had invited Biden but told CNN: “I don’t have any travel to speak to or announce, with respect to Israel.” Michael Capponi, the head of the Global Empowerment Mission aid agency, which has stockpiled relief supplies on the Egyptian side of the border, said on Monday morning that authorities in Cairo had said the crossing would be opened “most likely in days to come”. He said: “The US wants to ensure proper checking of trucks occurs so weapons are not filtered to Hamas. I think that’s [the] main issue. The events unfolding in the region have the potential to become one of the biggest humanitarian crisis in recent history. “It is our duty and obligation to help all human beings who are caught in the crossroads of this war. Our first trucks of aid are arriving to the Rafah gate queue today. We are coordinating deliveries with UN agencies inside Gaza.” The UN humanitarian chief, Martin Griffiths, is expected in Cairo on Tuesday and is also expected to visit Israel this week to make a plea to allow life-saving assistance into Gaza. Before setting off, Griffiths called for Hamas to release its hostages immediately and said people trapped in Gaza should be able to move out of harm’s way. A planeload of medical supplies from the World Health Organization arrived on the Sinai peninsula, on the Egyptian side of the border, over the weekend. The shipment included trauma dressings and medication for 1,200 wounded patients, as well as medication for 1,500 patients with heart problems and other conditions, together with basic health items for 300,000 people, including pregnant women. The World Food Programme is assembling a truck convoy carrying 100 tonnes of food parcels and 15 tonnes of fortified biscuits on the Egyptian side of the border. Doctors at hospitals in Gaza have said thousands could die if emergency medical help does not arrive soon. They said many patients, including newborn infants in intensive care, could not be moved in compliance with the Israeli order for a million civilians to move to the southern half of the enclave.