Sen. Bernie Sanders (I-Vt.) on Sunday called on President Joe Biden to deny Israeli Prime Minister Benjamin Netanyahu more U.S. funding for his “war machine” unless Israel allows for more humanitarian aid to reach civilians in Gaza.

In an interview with CBS’s “Face The Nation,” Sanders said the ongoing offensive, which has already killed over 31,000 Palestinians and displaced millions, according to local officials, cannot be allowed to continue with the blessing of the U.S.

“We are looking at the possibility of hundreds of thousands of children starving to death,” Sanders said. “The United States of America cannot be complicit in this mass slaughter of children.”

Health officials in Gaza have said 20 people, including children, have died of malnutrition, according to The Associated Press, with many warning the situation is likely to deteriorate even further.

Taking a harsher stance toward Netanyahu to pressure him to take into account the suffering of innocent Palestinians, Sanders added, would be both the moral thing to do and “good politics” for Biden.

“The truth is, whether you’re a conservative Republican or a progressive, you do not want to see children in Palestine starve to death,” Sanders said.

Meanwhile, Netanyahu is planning to expand his country’s offensive to the southernmost city of Rafah, where millions of Palestinians have sought refuge during the conflict, appearing to ignore calls from the U.S. to back away from that plan.

Sanders warned attacking Rafah would be an “unmitigated disaster.”

“My view is, of course, we cannot support an attack of that kind on Rafah,” Sanders told CBS’s Margaret Brennan. “Bottom line is, though, Netanyahu has got to be told no more money for his war machine, unless there is humanitarian aid coming in to feed the people.”

Biden has warned Netanyahu against going ahead with a Rafah offensive, but said ultimately even if Israel did proceed with its plans, he wouldn’t pull U.S. funding for the country.

“It is a red line, but I’m never going to leave Israel,” Biden told MSNBC. “The defense of Israel is still critical. So there’s no red line where I’m going to cut off all weapons so they don’t have the Iron Dome to protect them.”

But Netanyahu told Axel Springer his only “red line” is to make sure Israel never goes through another attack like the one his country experienced on Oct. 7, when Hamas killed 1,200 people in Southern Israel and took hundreds of hostages, some of which still remain in its custody.

So far, cease-fire talks between Israel and Hamas brokered by Egypt, Qatar and the U.S. have stalled despite earlier hope for a pause to hostilities by the beginning of the holy month of Ramadan.