Former Secretary of State Hillary ClintonHillary Rodham ClintonAgriculture head backs Perez in DNC race Hillary Clinton tweets well-wishes to Bushes Chelsea Clinton: We must keep fighting MORE said Wednesday she is skeptical Iran will strike a deal to curtail its nuclear program.
Clinton, in a speech to the American Jewish Committee's global forum in Washington, suggested the chance of a deal is less than 50-50.
The United States and other allies are meeting with Iranian officials in Vienna this week to begin talks on a final nuclear deal. An interim deal last year eased some sanctions on Iran in exchange for concessions meant to limit Iran's program.
Clinton argued that Iran has not lived up to all of its commitments and said the next few months will be crucial. She said the U.S. must be willing to walk away from a bad deal.
"To get there we will have to be tough, clear eyed and ready to walk away and increase the pressure if need be," she said. "No deal is better than a bad deal. From my perspective, we cannot and should not accept any agreement that endangers Israel or our own national security. Now it is worth noting that even if an agreement is reached, Iran's support for terrorist and its aggressive behavior in the region remains a threat."
Clinton on Wednesday defended the administration's strategy of engagement and pressure toward Iran during her time at the State Department. The United States was in a good position when she left office to see if Iran would come to the table, she said.
Clinton, who is likely to run for president in 2016, also spoke of the failed peace talks between Israel and the Palestinians.
She said it is not hard to imagine what a final deal will look like but said it will require "mobilizing the political will" of all parties involved.
She reaffirmed the United States' commitment to Israel, saying, “America’s commitment to Israel’s security will never waver. That is not a hard choice," referencing the title of her new book.
The next decade, Clinton predicted, would see a contest between authoritarianism and democracy.
"I would hasten to add, I would like to see our own democracy work a little more smoothly in order to set a better example and to deal with our own problems here at home," Clinton said to applause.