Bernie Sanders has stepped up his calls for a humanitarian pause in Gaza, demanding an immediate stop to Israeli bombing and an end to the killing of thousands of “innocent men, women and children” in the enclave. In some of his strongest words in the 30-day war, the independent US senator from Vermont decried the 7 October Hamas attack inside Israel. He labelled Hamas as an “awful terrorist organization” that had “slaughtered 1,400 people in cold blood”, reiterating his belief that Israel had the right to defend itself. But speaking on CNN’s State of the Union on Sunday, Sanders said the death of civilians had to stop. “What Israel does not, in my view, have a right to do is to kill thousands of thousands of innocent men, women and children who had nothing to do with that attack,” he said. The senator added: “There’s not enough food, there’s not enough water, medicine, fuel. You’ve got a humanitarian disaster, it has to be dealt with right now.” Sanders continues to be influential on the progressive flank of US politics at a time of deepening rifts on the left over the response to the war. He walks a fine line, condemning the civilian death toll caused by Israeli air strikes while resisting calls for a full-on ceasefire. “I don’t know how you could have a permanent ceasefire with an organization like Hamas which is dedicated to destroying the state of Israel … and has got to go,” he told CNN. Several members of the progressive wing of the Democratic party have gone further, demanding an immediate ceasefire and challenging the Biden administration’s plans to send emergency military aid package to Israel. In a newly-released video, the only Palestinian American member of Congress, Rashida Tlaib, accused Joe Biden of supporting “genocide” and demanded he back a “ceasefire now”. Sanders declined CNN’s invitation to condemn Tlaib, saying: “We don’t have to quibble about words … Rashida is a friend of mine, her family comes from Palestine, I think she’s been shaken, as all of us are, about what is going on right now.” Republicans in the US House last week passed a $14.3bn military aid package for Israel. Democrats have indicated they are likely to oppose any similar bill that reaches the upper chamber given its inclusion of spending cuts for the Internal Revenue Service (IRS). Sanders said that he would judge any aid package when it reaches the Senate, but said it should be made contingent on ending civilian deaths. “It’s terribly important that, as we debate that, to say to Israel, ‘You want this money, you got to change your military strategy’.” Sanders’ call for an end to the bombing to allow humanitarian aid to reach desperate Palestinians came as the US secretary of state Antony Blinken made a surprise visit to the West Bank on Sunday. Blinken met the Palestinian president Mahmoud Abbas and, according to read-outs of the conversation, expressed Washington’s desire that the Palestinian Authority, which Abbas heads, should be central in the running of any post-Hamas Gaza. The Biden administration continues to press for a humanitarian pause in the bombardment, both to allow humanitarian aid in and to assist with the release of the more than 240 hostages captured by Hamas on 7 October. Speaking on CBS News’s Face the Nation, the deputy national security adviser Jonathan Finer said that while the Biden administration supported Israel’s mission “to go after Hamas” it was also urging more care by the Israeli military to spare the lives of civilians. The current death toll, as released by the Hamas-run ministry of health, is more than 9,770 Palestinians. Finer said that the US had had “many direct conversations” with the Israeli government emphasising “their obligation to distinguish between civilians and fighters … Some of the images and events that we’ve seen transpire in Gaza have been heartbreaking for all of us.” So far the US call for a reduction in the civilian death toll has failed to sway Israeli military thinking. The Israeli prime minister, Benjamin Netanyahu, has dismissed the idea of a temporary ceasefire until all of the hostages are released. Gilad Erdan, the Israeli ambassador to the UN, ruled out any humanitarian pause on Sunday. Speaking to CNN’s State of the Union, he said such a break in the air strikes and ground incursion would allow Hamas to “rearm and regroup and prevent us from achieving our goal to destroy Hamas’s terrorist capabilities”. Erdan claimed “there is no humanitarian crisis in Gaza”. He also insisted that Israel “never intentionally targets civilians. We do everything that is possible to minimize and mitigate civilian casualties.” Fears that the Gaza fighting will spill over into a wider regional war are also roiling political debate in the US. On Monday, a bi-partisan resolution will be presented in the US senate warning Iran not to unleash further fighting on Israel’s northern border through the powerful Iranian-backed militia, Hezbollah. The Republican senator who has co-authored the resolution, Lindsey Graham, told CNN that the resolution threatens Iran with a US military response should it open up a second front against Israel. “The resolution puts Iran on notice that all this military force in the region will be coming after you if you expand this way by activating Hezbollah or killing Americans through your proxies in Syria and Iraq,” he said. Richard Blumenthal, Graham’s Democratic partner behind the resolution, called the non-binding motion “aggressive but absolutely necessary”. “The key word here is deterrence – the purpose of the resolution is to deter Iran by showing we’re going to be behind the president as he seeks to stop the war from widening or escalating.”