Warning the international community to "beware" Iran's intentions, Israeli Prime Minister Benjamin Netanyahu urged the United States and other negotiators to demand as part of nuclear talks that the regime "change its genocidal policy" toward the Jewish state.

"This is a regime committed to our destruction," Netanyahu said, at a forum on U.S.-Israel relations hosted by the Brookings Institution.

The Israeli leader continued to sound a deeply skeptical tone toward the short-term deal struck last month in Geneva to scale back Iran's nuclear efforts in exchange for rolling back sanctions. He said any long-term deal must end Iran's "military nuclear capability."

But Netanyahu said the talks also must include an "unequivocal demand" for Iran to not just tweak the "minutiae" of its nuclear program, but change its entire policy toward Israel.

"I don't think any of us can overstate the Iranian danger," he said.

Netanyahu spoke a day after President Obama addressed the same forum and cast doubt on the deal with Iran.

"If you ask me what is the likelihood that we're able to arrive at the end state ... I wouldn't say that it's more than 50-50," Obama said. "But we have to try."

Netanyahu and Obama have been at odds over the deal with Iran, and the remarks by Obama could have been an effort to show the Israeli leader he shares his skepticism.

Netanyahu on Sunday stressed that the Israel-U.S. bond is an "indispensable alliance" in this effort and the two nations will continue to work together on Iran.

But he said "the jury is still out" on Iran's intentions.

He questioned why Iran continues to take such steps as developing ballistic missiles, and said any final deal should make sure Iran is not a "threshold nuclear weapon state," allowed to cross that line when it wishes.

He said diplomacy is the preferred course, but said the military option must be on the table and suggested sanctions could even be increased during talks.

Israel is "prepared to do what is necessary," he said.

The goal of the talks is to eliminate the possibility of Iran assembling a nuclear arsenal, even if any deal might let Iran continue enriching uranium at lower levels not easily convertible into weapons-grade material.

Israel has complained that the short-term deal struck in Geneva gave Iran too much leeway and has voiced concern about where these talks will lead.

Secretary of State John Kerry, who opened his address to the forum with a discussion of the state of the Israeli-Palestinian peace talks, echoed Obama's skepticism of Iran when he said, "As we enter negotiations for a final, comprehensive agreement, we absolutely do so with our eyes wide open, and, as yet, I have to say, unconvinced that Iran will absolutely make all the decisions, the hard decisions necessary to reach such an agreement."

The Associated Press contributed to this report.