WASHINGTON U.S. Vice President Joe Biden said on Saturday there was a "less than even shot" of a nuclear deal with Iran but that it was still worth pursuing.
Biden, speaking at a forum on the Middle East at the Brookings Institution think tank, rejected calls for more sanctions against Tehran over its nuclear program because "this is not the time to risk a breakdown when we still have a chance for a breakthrough."
Biden said the sanctions imposed by the United States and allies were working by slowing Iran's economy, as well as its nuclear program.
"It's frozen the program, it's given us a shot for a peaceful solution," he said. "I tell you, I think it's a less than even shot but it's a shot, nonetheless."
Biden said that while the United States and Israel have tactical disagreements, Washington remained fully dedicated to Israel's security.
"We will not let Iran acquire a nuclear weapon - period," he said. "End of discussion. Not on our watch."
Last month Iran said it would not make excessive concessions on its nuclear program, which Tehran says is for energy-creation purposes, as part of a 12-year dispute.
(Writing by Bill Trott; Editing by Sandra Maler)