When top Biden administration officials conveyed their frustrations over the "unacceptable and unsustainable" situation in Gaza to Benny Gantz, they were delivering their message to Israeli Prime Minister Benjamin Netanyahu's chief political foe. Vice President Kamala Harris and Secretary of State Antony Blinken met with Gantz, a member of the Israeli war cabinet, as the US seeks to ratchet up pressure on the Netanyahu government to allow more aid into Gaza. Those calls have gone largely unheeded as the humanitarian crisis deepens and ceasefire talks have yet to reach a breakthrough. Gantz's decision to travel to Washington, DC, was not sanctioned by the Israeli government, meaning he was not accompanied by the Israeli ambassador in his meetings, according to an official familiar. The trip ignited controversy within Israel and spurred the immense ire of Netanyahu, who maintains a tenuous hold on leadership. US officials argued it made sense to meet with Gantz, who is widely seen to be a leading contender to be the next Israeli Prime Minister. Frustration is mounting within the Biden administration about the Netanyahu government's continued refusal to open more land crossings for critically needed aid to reach the people of Gaza. The US and its partners have resorted to airdropping food into Gaza. The desperation of the situation was laid bare last week when more than 100 people were killed in an incident where Israeli troops opened fire while hungry Palestinians were awaiting a food convoy. On Monday, President Joe Biden reiterated that there are "no excuses" for Israel not to allow more aid into the besieged strip. When Gantz met with Harris and national security adviser Jake Sullivan behind closed doors on Monday, he was told repeatedly that Israel must do more to alleviate the humanitarian crisis, according to an administration official familiar with the conversations. According to an Israeli official, Gantz emerged from those meetings with deep concerns and some surprise about the state of US-Israeli relations over the war in Gaza. Gantz was surprised by how critical the White House was about the humanitarian situation in Gaza and a potential military offensive into Rafah, an Israeli official said. He also emerged clear-eyed about the administration's deep and growing mistrust of Netanyahu. During the meeting, Harris made clear that the administration needs Israel to do more to address the humanitarian situation in Gaza in order to ensure continued robust American support for Israel. "Help us help you," was the message, according to an Israeli official. To that end, Gantz sought to show that he understood the administration's concerns and gave assurances that Israel is prepared to and will evacuate civilians before any offensive into Rafah, the Israeli official said. US officials were emphatic with Gantz that additional humanitarian crossings need to be opened up to let many more trucks carrying aid to get into the strip. "We've raised these things before, but there's greater urgency now on the humanitarian front," the administration official said. Blinken raised the same urgency in his meeting with Gantz at the State Department on Tuesday. "We want to see another crossing open and it's something we're engaged with quite directly with the Israeli Government, and that includes in the conversation that the Secretary had with Minister Gantz today," State Department spokesperson Matthew Miller said Tuesday. "He was quite direct and quite frank about the seriousness of the situation on the ground and the fact that it is incumbent on everyone involved to do more to get aid in urgently, as soon as possible." The two also discussed the negotiations to reach an immediate, temporary ceasefire that would secure the release of hostages held by Gaza. An Israeli government official said Monday that Gantz "does not represent" the Israeli government during his trip and the Israeli Ambassador to the US was instructed by Netanyahu's office not to handle Gantz's visit. Despite this, Biden administration officials maintained it was important to grant Gantz the meetings. Gantz is "one of three members of the war cabinet who has a critical vote and a critical stake in how this war is conducted," State Department spokesperson Matthew Miller said Monday. "He has a critical voice in the delivery of humanitarian assistance; he's an important figure in the sitting government of Israel, and so that's why we engage with him." — CNN