US President Barack Obama said on Monday that the bond between the US and Israel is unbreakable, despite tensions over differences in opinion with regard to efforts to seal a landmark atomic deal with Iran.In an interview with Reuters at the White House, Obama said that a rift over Israeli Prime Minister Benjamin Netanyahu's planned speech to Congress opposing the Iran deal on Tuesday was a distraction that would not be "permanently destructive" to US-Israeli ties.But he said there was a "substantial disagreement" between his administration and the Israeli government over how to achieve their shared goal of preventing Iran from acquiring nuclear weapons."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.The US goal is to make sure "there's at least a year between us seeing them try to get a nuclear weapon and them actually being able to obtain one," he added.Israel fears that Obama's Iran diplomacy, with an end-of-March deadline for a framework nuclear agreement, will still allow its arch-foe to develop an atom bomb. Tehran denies it is seeking nuclear weapons.Netanyahu has spoken scathingly about a possible deal, saying negotiators appear to have given up on a pledge to prevent Iran from acquiring nuclear weapons. He says a nuclear-armed Iran would pose an existential threat to the Jewish state.Obama sought to downplay the long-term damage from the row over Netanyahu's speech to Congress, saying the rift was not personal but a matter of policy."As a matter of policy, we think it's a mistake for the prime minister of any country to come to speak before Congress a few weeks before they're about to have an election. It makes it look like we are taking sides," Obama said, referring to Israel's March 17 election.Obama said Netanyahu had been wrong before with his opposition to a 2013 interim deal with Iran, pointing out that Iran had rolled back elements of its program during that time.The White House last week denied a report that the United States and Iran were exploring a possible 10-year deal that would initially freeze Iran's nuclear program but gradually allow it to increase activities that could enable it to produce nuclear arms in the last years of the agreement.In a speech on Monday to the American Israel Public Affairs Committee (AIPAC), the largest US pro-Israel lobby, Netanyahu again warned that a nuclear deal could threaten Israel's survival while insisting the US-Israeli relationship was "stronger than ever."Asked about the prospects for a final deal with Iran, which has a June 30 deadline, Obama said that a key doubt was whether Iran would agree to rigorous inspection demands and the low levels of uranium enrichment capability they would have to maintain. "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.A comprehensive nuclear deal is seen as crucial to reducing the risk of a wider Middle East war, at a time when Iran is deeply involved in conflicts in Syria and Iraq.