Obama assures Netanyahu on efforts to stop Iran's nuclear program President Obama sought to convince Israeli Prime Minister Benjamin Netanyahu on Monday that he would not allow Iran to develop a nuclear weapon, but their meeting concluded with U.S. officials unsure whether the president had succeeded in persuading the Israelis to hold off on unilateral military action. The leaders met for about two hours in the Oval Office at a crucial juncture in Obama's effort to restrain Iran's nuclear ambitions and win the trust of Israel, the closest U.S. ally in the Middle East. Israeli officials afterward called the talks "positive" and said both sides agreed on the need to continue economic and political pressure on Iran. President Obama say he prefers to use diplomacy to prevent Iran from obtaining nuclear weapons, but he is making it clear that he won't "hesitate to use force" when necessary to defend the U.S. and its interests. Rachel Weiner Matt DeLong But hours after the meeting, Netanyahu renewed his warning that time for diplomacy was running out. In a fiery speech to a Jewish American advocacy group, he said recent economic sanctions had not slowed Iran's march to nuclear-weapons capability. "None of us can afford to wait much longer," Netanyahu told a cheering audience at the American Israel Public Affairs Committee's annual policy conference in Washington. As prime minister of Israel, I will never allow my people to live in the shadow of annihilation. At the White House meeting, Obama made clear to Netanyahu that his policy is not to contain an Iranian nuclear arsenal but to prevent Iran's leaders from developing one, administration officials said. In making his case for diplomacy over a military strike, Obama also assured Netanyahu that Israel has the right to act in its own national security interests. "Our assessment is that they have not made a decision," said a senior administration official, who spoke on the condition of anonymity to discuss the private meeting. While I can't say for sure that we bought time, I think they certainly feel more assured about our intentions. They can say and feel that the ball had moved forward in that respect. In public and private statements in recent days, Obama urged Israel to refrain from a military strike against Iran's nuclear facilities, a move that many in the administration feared would set off a regional war in the volatile Middle East. Such a conflict in the oil-rich region would send gasoline prices even higher, exacerbating an election-year threat to Obama. A few months would allow for the full array of economic sanctions against Iran to take effect this summer, including an embargo on its lifeblood oil industry and banking sector. That time would also help preserve the international coalition that is aligned against Iran's nuclear program - a fragile diplomatic front that administration officials say would shatter if Israel struck prematurely. "We do believe that there is a window that allows for a diplomatic resolution to this issue, but ultimately the Iranians" regime has to make a decision to move in that direction, a decision they have not made thus far," Obama said, with Netanyahu sitting at his side. I reserve all options, and my policy here is not going to be one of containment. My policy is prevention of Iran obtaining nuclear weapons.