The US pledged to send more arms to Israel on Thursday ahead of an expected ground assault in Gaza against Hamas, as the UN warned food and water supplies were running dangerously low in the blockaded enclave. As America’s top diplomat flew into Israel following Saturday’s surprise cross-border assault by Hamas, the UK announced it would send two navy ships and would begin surveillance flights in its own show of support. Antony Blinken, the US secretary of state, pledged his country’s support for Israel “today, tomorrow, every day”.He told the prime minister, Benjamin Netanyahu, on a visit to the region that Israel “may be strong enough on your own to defend yourself but, as long as America exists, you will never, ever have to. We will always be there by your side”. The declaration of solidarity came as Israeli troops continued to build close to Gaza before an expected ground invasion. Intense bombing of the narrow territory that is home to 2.3 million Palestinians continued for a sixth consecutive day as concerns mounted about the humanitarian crisis. Israel declared war on Hamas on Saturday after hundreds of Islamic militants broke through the Gaza security fence to massacre approximately 1,300 people in Israel, including children. Gunmen seized a further 150 people, who are now being held hostage inside Gaza. The death toll in Gaza rose above 1,400, including 447 children and 248 women, Gaza’s health ministry said, as Israel Defence Forces strikes continued to pound buildings and neighbourhoods. Although Blinken offered unwavering support to Israel and condemned Hamas’s “reign of terror”, he also spoke of the Palestinian people’s “legitimate aspirations to live with equal measures of security, freedom, justice, opportunity and dignity”. He told Netanyahu: “I come before you not only as the United States secretary of state but also as a Jew” and “a husband and father of young children … “It’s impossible for me to look at the photos of families killed, such as the mother, father and three small children murdered as they sheltered in their home in Kibbutz Nir Oz, and not think of my own children.” He added that he had seen photographs and videos in meetings including of a baby riddled with bullets, soldiers beheaded and young people burned alive in their cars or hideaways. “It’s simply depravity in the worst imaginable way,” Blinken said. One picture was posted on X, formerly known as Twitter, by the official account of the Israeli government on Thursday. “This is the most difficult image we have ever posted but we need each and every one of you to know,” the post read, above a picture of a dead baby whose face had been blurred. “This happened.” Netanyahu said he appreciated US support, adding that Hamas, which has ruled Gaza since 2007, should be treated like Islamic State. “Just as Isis was crushed, so too will Hamas be crushed,” he said. In an indication that the conflict is expected to be protracted, some countries – including the UK, Canada and Belgium – began evacuating their nationals from Israel. Israel said there would be no humanitarian break to its siege of the Gaza Strip until all hostages held by Hamas were released. The energy minister, Israel Katz, wrote on social media that no “electrical switch will be turned on, no water hydrant will be opened and no fuel truck will enter” until the “abductees” were free. The UN considers the tightened siege a war crime, and the 16-year-blockade is illegal under international humanitarian law. “It’s a dire situation in the Gaza Strip that we’re seeing evolve with food and water being in limited supply and quickly running out,” said Brian Lander, the deputy head of emergencies at the UN World for Food Programme. The World Health Organization warned that the health system in the Gaza Strip is “at breaking point” and “time is running out to prevent a humanitarian catastrophe”. Residents were sifting through rubble looking for survivors and bodies. Eighteen healthcare facilities and 20 ambulances had been affected by the bombardment, and 11 healthcare workers killed, the World Health Organization said. The UN said late on Wednesday the number of people displaced by the airstrikes had soared by 30% within 24 hours to 339,000 – two-thirds of them crowding into UN schools. Palestinian media said that bombing had killed the brother of Mohammed Deif, Hamas’s military commander, and a senior commander from Palestinian Islamic Jihad. Hazem Balousha, the Guardian’s reporter in Gaza, reached by phone on Thursday morning, said the strip’s residents had been told that hospitals had stopped admitting all but emergency cases. Rafah, Gaza’s crossing point with Egypt, remained closed, and the only power station ran out of fuel on Tuesday, leaving the strip powered by scattered private generators. Those will shut off as well if fuel is not allowed in and the Red Cross has pleaded for fuel deliveries in order to prevent overwhelmed hospitals from “turning into morgues”. In Israel, the reported death toll climbed to 1,300. Lt Col Richard Hecht, an Israeli military spokesperson, told reporters that forces were preparing for a ground assault but that the political leadership had not yet ordered one. Netanyahu, who now leads a newly formed unity government and war cabinet, including members of the opposition, has vowed to “crush and destroy” Hamas. Benny Gantz, the leader of the centrist National Unity party, a former defence minister and a strident critic of Netanyahu’s current far-right government, said: “We are all in this together. This is not a political partnership, but rather a unity of fate. This is the time to close ranks and to win.” Blinken is expected to meet the Palestinian Authority president, Mahmoud Abbas, on Friday before visiting Qatar. Abbas, whose Fatah movement lost control of Gaza to Hamas in 2007, said on Thursday: “We reject the practices of killing civilians or abusing them on both sides because they contravene morals, religion and international law,” according to official Palestinian news agency Wafa. Blinken’s visit coincides with the arrival of a US aircraft carrier in the region, amid fears that the war could escalate, drawing in Hezbollah, the Iran-backed Lebanese militant group, and Palestinian factions in the occupied West Bank and Jerusalem. In the West Bank, clashes in several areas have erupted between Palestinians and IDF troops, as well as Israeli settlers. A ground offensive in Gaza is likely to bring even higher casualties on both sides in brutal house-to-house fighting. Israel has mobilised an unprecedented 360,000 reservists, massed additional forces near the strip, and evacuated tens of thousands of nearby residents. Strategic planning has been complicated by the presence of Israeli hostages, among them children and elderly people, inside the Gaza Strip. Israel’s Army Radio, citing a foreign diplomat, said that those kidnapped had been spread out across the enclave, some being held in private houses, and the factions themselves were not sure of the total number of hostages.