Updated 6:27 pm ET, 12/7/2013
Washington (CNN) - President Barack Obama defended his administration's nuclear deal with Iran, arguing that the ground had been set for a comprehensive agreement that would make the United States, Israel and the Middle East safer, but warning that all options would remain on the table if a deal fell through.
"The best way for us to prevent Iran from getting a nuclear weapon is for a comprehensive, verifiable, diplomatic resolution, without taking any other options off the table if we fail to achieve that. It is important for us to test that proposition during the next six months," he said Saturday at the Saban Forum, a policy summit organized by the Brookings Institution to discuss issues surrounding the Middle East and U.S.-Israeli relations.
"If at the end of six months, it turns out that we can't make a deal, we're no worse off, and in fact we have greater leverage with the international community to continue to apply sanctions and even strengthen them," he continued.
One of the most vocal critics of the deal is Israeli Prime Minister Benjamin Netanyahu. On the eve of the agreement, he told CNN's Candy Crowley that no deal was better than a bad deal and, "This is a bad deal."
Obama must have been watching.
"If we can't get there, then no deal is better than a bad deal. But presuming that it's going to be a bad deal, and as a consequence, not even trying for a deal, I think, would be a dire pursuit," he said.
Throughout the 45-minute conversation with Haim Saban, the Israeli-American media mogul and namesake of Brookings' Saban Center, Obama stressed that relations with Israel were still strong. Military coordination, intelligence cooperation, and security support have never been better, he said.
Still, the president was surprisingly honest about where there are differences between him and Netanyahu.
"There are times where I, as president of the United States, am going to have different tactical perspectives than the prime minister of Israel, and that is understandable," he said.
He made clear that he respects Israel's need to look after its own security first, but argued that getting Iran to completely abandon its nuclear aspirations was chimerical.
"One can envision an ideal world in which Iran said we'll destroy every element and facility and - you name it, it's all gone. I can envision a world in which Congress passed every one of my bills that I put forward. I mean, there are a lot of things that I can envision that would be wonderful," he joked.
Ultimately, however, a deal in which Iran is granted nuclear power for civilian purposes in exchange for intrusive inspections is the best, most realistic option, he argued.
That concession has outraged some in Israel and the U.S., who argue it is a naive appeasement that gives Iran the right to enrichment. Obama believes otherwise.
"There's nothing in this agreement or document that grants Iran a right to enrich," he said. "If negotiations break down, there will be no additional international recognition that's been obtained, so this deal goes away and we're back to where we were before the Geneva agreement."
Obama pushed further, saying that if a comprehensive deal was reached, enrichment capability would be so limited and inspections so intrusive that "as a practical matter," Iran would not have the breakout capacity to build a nuclear weapon.
Iranian leaders interpret the deal differently. After Geneva, Rouhani said the outcome means world powers have "recognized Iran's nuclear rights," including the right to enrich uranium.
"This right has been explicitly stipulated by this agreement, stressing that Iran will go on with enrichment," he said.
Like other aspects, it is an important and ambiguous detail that for the moment allows both sides to claim victory and going forward could be worked out in this comprehensive agreement down the road.
And just how far away is that kind of deal?
"If you asked me what is the likelihood that we're able to arrive at the end state that I was describing earlier, I wouldn't say that it's more than 50-50," said Obama. "But we have to try."
–CNN's Holly Yan, Josh Levs, and Tara Kangarlou contributed to this report.