Israel's aggressive bombing campaign in Gaza is causing international support to wane due to the high number of civilian casualties.
President Joe Biden made the remark Tuesday as Canada, Australia and New Zealand called for urgent efforts towards a ceasefire.
"Israel's security can rest on the United States, but right now it has more than the United States. It has the European Union, it has Europe, it has most of the world supporting them," Biden said to donors during a fundraiser, according to a transcript provided by the White House.
"They're starting to lose that support by indiscriminate bombing that takes place," Biden added.
The president also said Israeli prime minister Benjamin Netanyahu must shake up the composition of his Likud-led cabinet, which experts have described as the most right-wing and extreme in Israeli history.
"Israel has a tough decision to make. Bibi has a tough decision to make. There's no question about the need to take on Hamas. There's no question about that. None. Zero," Biden said. "I think he has to change with this government. His government in Israel is making it very difficult for him to move."
"They don't want a two-state solution. They don't want anything having to with the Palestinians," Biden added. "You cannot say there's no Palestinian state at all in the future. And that's going to be the hard part."
Nonetheless, Biden said the U.S. will continue to do "every single thing in our power" to hold Hamas accountable because they are "brutal, ugly, inhumane people, and they have to be eliminated."
"We're not going to do a damn thing other than protect Israel in the process. Not a single thing," he said.