President Obama on Sunday defended his blueprint for curtailing Iran’s nuclear capabilities, using a speech before Israel’s largest U.S. advocacy group to combat Republicans’ election-year claims that the president hasn’t been supportive enough of America’s chief ally in the Middle East.

Obama told the nearly 13,000 people at the American Israel Public Affairs Committee conference that he preferred taking a diplomatic approach to the rising threat of Iran but that he wouldn’t eliminate any of the methods at his disposal to stop Iran from obtaining nuclear weapons.