The US Vice President is calling for an "immediate ceasefire" for six weeks in Gaza.
Kamala Harris said it would get Israeli hostages out and get a significant amount of aid into the war-ravaged Palestinian territory.
She said people were "starving" and Israel needed to increase the flow of life-saving assistance to ease what she described as "inhumane" conditions and a "humanitarian catastrophe". Her comments are among the strongest by a senior US official over the crisis.
Ms Harris also said there is a "deal on the table" and Hamas "needs to agree to that".
"Let's get a ceasefire. Let's reunite the hostages with their families. And let's provide immediate relief to the people of Gaza," she said on Sunday.
Although a Hamas delegation is in Egypt for the latest truce talks, Israel has reportedly boycotted them.
Israeli media says it is because Prime Minister Benjamin Netanyahu has not got an answer from Hamas on two questions - a list of hostages who are alive in Gaza and the number of Palestinian prisoners Hamas wants released in exchange for each hostage.
US efforts in the region have increasingly been hampered by Mr Netanyahu's hardline cabinet, which ultra-nationalists dominate.
There are deep disagreements between Mr Netanyahu and US President Joe Biden over how to alleviate Palestinian suffering in Gaza and come up with a post-war vision for the enclave.
A 'Ceasefire Now' banner on Dublin's Liberty Hall, 4-1-24. Image: SIPTUOn Saturday, the US airdropped aid into Gaza after dozens of Palestinians rushing to grab food from trucks were killed by Israeli forces last Thursday.
Speaking in Alabama, Ms Harris said: "People in Gaza are starving. The conditions are inhumane and our common humanity compels us to act.
"The Israeli government must do more to significantly increase the flow of aid. No excuses."
A senior US official had said the path to a ceasefire was "straightforward and there's a deal on the table", with mediators returning to Egypt hoping to reach an agreement before Ramadan begins in a week.
The unidentified official spoke to the Reuters news agency ahead of the talks in Cairo, billed as the final hurdle to a six-week ceasefire.
Earlier on Sunday, the US said a deal had already been "more or less accepted" by Israel and was waiting for approval by Hamas militants.
But after the Hamas delegation arrived, a Palestinian official said the deal was "not yet there". Hamas also reportedly wanted a permanent ceasefire to be part of any deal.
Palestinians walk past a building destroyed in the Israeli bombardment of the Gaza Strip in Gaza City, 3-1-24. Image:Associated Press / AlamyThe latest war started after Hamas launched a cross-border attack on southern Israel on October 7th last year, killing 1,200 people, mostly civilians, and taking more than 250 others hostage.
Israel retaliated with strikes and a military ground assault in Gaza which have so far killed more than 30,000 people, around two-thirds of them women and children, according to the Hamas-run health ministry.
Around 80% of the population of 2.3 million have fled their homes, and UN agencies say hundreds of thousands are on the brink of famine.
More than 100 hostages in Gaza have been released.
US Vice-President Harris is due on Monday to meet top Israeli politician Benny Gantz, who will also have talks in Washington with US Secretary of State Antony Blinken, national security adviser Jake Sullivan, and Republican and Democratic members of Congress.
Although Mr Gantz is in Mr Netanyahu's war cabinet, he is also a centrist political rival and is thought to have been rebuked by the Israeli prime minister for those planned discussions in America.
An official from Mr Netanyahu's Likud party said Mr Gantz's visit was not authorised by the party leader.
The US has vetoed a number of United Nations resolutions calling for a ceasefire in Gaza.
Reporting by: IRN
