The relationship between the United States and Israel "transcends politics, and it always will," US Ambassador to the United Nations Samantha Power told the AIPAC conference in Washington on Monday.
Power spoke a day before a controversial address to the US Congress by Israel's Prime Minister Benjamin Netanyahu, who addressed the AIPAC conference on Monday.
Power said the Obama administration preferred a diplomatic route to prevent Iran from building a bomb, but suggested Obama would turn to other tactics if a deal cannot be reached.
"The United States of America will not allow Iran to obtain a nuclear weapon. Period. If diplomacy should fail, we know the stakes of a nuclear-armed Iran as well as everyone here. We will not let it happen," Power told the 16,000 supporters of AIPAC gathered in Washington.
US and Israeli officials have reported progress on a deal that would freeze Iran's nuclear program for ten years, but allow it to slowly ramp up in the later years of an agreement. Netanyahu has vigorously criticized the contours of such an agreement, saying it suggested the US and its partners had "given up" on stopping Iran from being able to get a bomb.
Kerry warns Netanyahu of disclosing details about nuclear agreement
Meanwhile, US Secretary of State John Kerry has traveled to Geneva for further talks with Iran. He warned anyone from disclosing revealing details of a nuclear deal that the US and other world powers are currently trying to conclude with Iran.
While Kerry did not mention Netanyahu by name, he told reporters in Geneva he was "concerned by reports" that "selective details" of the deal aimed at curbing Tehran's nuclear program would be revealed in the coming days. His comments come after a official in Jerusalem said Israel knew about the emerging agreement and that the prime minister would elaborate in his congressional address on Tuesday.
Kerry wasdue to meet his Iranian counterpart Mohammad Javad Zarif on Monday for talks on the Iran agreement. "The best way to deal with the question surrounding this nuclear programme is to find a comprehensive deal, but not a deal which comes at any costs," he told reporters. "We have made some progress, but we still have a long way to go, and the clock is ticking."
