Netanyahu will address a joint meeting of Congress on Tuesday, when he will argue that a nuclear deal with Iran could imperil Israel's survival.
Obama laid out the parameters of a potential agreement to Reuters, asserting that Iran must commit to freezing its nuclear program for at least 10 years for a deal to be reached. Obama said the likelihood of an agreement is not certain; a White House spokesman said odds were "only at best 50-50" Monday afternoon.
“If, in fact, Iran is willing to agree to double-digit years of keeping their program where it is right now and, in fact, rolling back elements of it that currently exist ... if we’ve got that, and we’ve got a way of verifying that, there’s no other steps we can take that would give us such assurance that they don’t have a nuclear weapon," Obama said in the interview.
Obama said a major hurdle would be Iran agreeing to exacting demands for inspection and keeping enriched-uranium levels low.
"But if they do agree to it, it would be far more effective in controlling their nuclear program than any military action we could take, any military action Israel could take and far more effective than sanctions will be," Obama said.
White House spokesman Josh Earnest said one of the objectives the United States is trying to reach by halting Iran's program is "is to prevent a nuclear arms race in the Middle East."
Netanyahu spoke Monday to thousands of attendees of the American Israel Public Affairs Committee's policy conference, where he said his planned speech to Congress is not meant to signal any disrespect for Obama, nor to insert political partisanship into the U.S.-Israel relationship. He was invited to give the speech by House Speaker John A. Boehner (R-Ohio). The White House was not consulted in advance.
Netanyahu likened U.S.-Israeli relations to those of a family that occasionally has disagreements but maintains an unbreakable bond.
Netanyahu's trip to Washington is extraordinary, both in the content of the speech he is scheduled to give Tuesday and the fissures that it has created between the Israeli government the White House, leading Jewish American groups and Jewish Democrats.
The White House said Obama would not meet with Netanyahu because the speech will be delivered about two weeks before Israel's March 17 election. Obama told Retuers he would be more than happy to meet with Netanyahu after election day.
"This is not a personal issue. I think that it is important for every country in its relationship with the United States to recognize that the U.S. has a process of making policy," Obama said.
Obama, as Secretary of State John F. Kerry said last week, asserted that Netanyahu has been wrong on Iran before, when he opposed a 2013 interim deal with the country.
"Netanyahu made all sorts of claims. This was going to be a terrible deal. This was going to result in Iran getting $50 billion worth of relief. Iran would not abide by the agreement. None of that has come true," Obama said. "It has turned out that, in fact, during this period we’ve seen Iran not advance its program. In many ways, it’s rolled back elements of its program."
Obama also said: “I would say that it's probably still more likely than not that Iran doesn't get to yes. But I think in fairness to them, they have been serious negotiators. And they've got their own politics inside of Iran. It is more likely that we could get a deal now than perhaps three or five months ago. But there are still some big gaps that have to be filled.”
Like President George W. Bush before him, Obama has publicly acknowledged that Iran has a right to build and operate nuclear power plants to generate electricity. The dispute between Iran and major world powers, including the United States, centers on a formerly clandestine program to enrich uranium. Low-enriched uranium, which Iran has produced in substantial quantities, can be used as fuel for nuclear power plants. But if further processed into highly enriched, "weapons-grade" uranium -- a step that Iran is not known to have taken -- it can be used as fissile material in nuclear bombs.