Vice President Joe Biden said President Obama is "not bluffing" when he says he will stop Iran from acquiring a nuclear weapon.
The U.S. commitment "is to prevent Iran from acquiring a nuclear weapon period, end of discussion, period," Biden told the American Israel Public Affairs Committee's annual policy conference in Washington on Monday.
"Prevent -- not contain, prevent," Biden said. "President Barack Obama is not bluffing."
Biden said other options should be exhausted before it comes to military action.
"If, God forbid, we have to act, it's important that the rest of the world is with us," he said.
AIPAC spokesman Marshall Wittmann said the lobby, which attracted 13,000 activists to its conference, was "very pleased" by Biden's statement "that the president is not bluffing in his commitment to prevent Iran from obtaining a nuclear weapon."
Wittman called the vice president's address "a very strong and eloquent speech."
Israeli Prime Minister Benjamin Netanyahu, following Biden in a satellite broadcast from his Jerusalem office, said Iran has yet to cross the red line Netanyahu set out last September, when he told the United Nations that an Iranian capability to weaponize uranium would constitute a pretext for military action.
Netanyahu dismissed the latest round of talks between the major powers and Iran on its suspected nuclear weapon as Iran "buying time."
The major powers, including the United States, have said they were encouraged by the talks and have planned new talks for this month.
Netanyahu said that words and sanctions would not stop Iran.
"Sanctions must be coupled with a clear and credible military threat if diplomacy and sanctions fail," he said.
Netanyahu said he and Obama would discuss Iran, the turmoil in Syria and the peace process with the Palestinians when the U.S. president travels to Israel later this month.
The Israeli leader said the "step-by-step" approach to peace with the Palestinians was the "realistic" path, a sign that he will push back against attempts to revive final-status talks. Notably, Netanyahu did not refer to a two-state solution as an outcome.