Hillary Rodham Clinton cast doubt on the interim nuclear weapons agreement with Iran, saying in a speech here Wednesday night that she is “personally skeptical” that Iran’s leaders would follow through on a comprehensive agreement to end Iran’s march toward nuclear weapons.

Still, the former secretary of state told a pro-Israel audience that she stands behind the Obama administration’s negotiations with Iran and commended the work of her successor, John F. Kerry.

Clinton said the United States should “give space for diplomacy to work” and avoid imposing new unilateral sanctions or any other actions that might lead any allies to back out of existing international sanctions against Iran.

“The odds of reaching that comprehensive agreement are not good,” Clinton said. “I am also personally skeptical that the Iranians would follow through and deliver. I have seen their behavior over years. But this is a development that is worth testing.”