U.S. Secretary of State John Kerry has dismissed hard-line comments this week by Iran's supreme leader, but warned that talks with Iran may yield no agreement if Tehran refuses to resolve outstanding issues.
Negotiators hope to clinch a deal to curb Iran's nuclear ambitions on or around June 30, but Kerry said on June 24 that won't happen if Iran refuses to make concessions sought by the United States and other world powers to fill out the broad parameters of a deal announced in April.
"It may be that the Iranians will not fill out the full measure of what was agreed on in Lausanne, in which case there will not be an agreement," he said at a news conference in Washington before leaving on June 26 to join the last round of negotiations in Vienna.
Whether or not Iran can satisfy the world that its nuclear program is entirely peaceful "will be determined in the last days, by whether or not the outstanding issues that we've been very clear about are in fact addressed," Kerry said. "If they are not addressed, there won't be a deal."
Still, Kerry sought to portray as typical posturing the red lines Ayatollah Ali Khamenei drew in a speech this week.
Khamenei rejected a long-term freeze on Iran's nuclear research and insisted that Iran will only sign a deal if international sanctions are lifted first -- demands the United States and its allies are unwilling to meet.
Kerry said the speech, along with highlights on Khamenei's official Twitter feed, were for "domestic political consumption."
"This is something that's been going on throughout the negotiations," Kerry said. "It is not new."
The negotiators "are not going to be guided by or conditioned by or affected or deterred by some Tweet that is for public consumption or domestic political consumption," he said. "What matters to us is what is agreed upon within the four corners of a document, and that is what is yet to be determined."
Kerry said neither he nor President Barack Obama will negotiate in public.
"I am not tweeting," he said. "I am not making speeches, neither is President Obama."
Meanwhile, Iranian state media reports that Foreign Minister Mohammad Javad Zarif will travel to Vienna on June 27 to join a final push for a comprehensive nuclear agreement with major powers.
The official IRNA news agency said on June 25, "On Saturday morning, he [Zarif] will join his deputies who are at the talks drafting the text of a comprehensive agreement."
Kerry's warning that the talks may produce no deal may have reflected the pressure he is under to come up with the toughest possible curbs on Iran's nuclear activities.
A group of prominent U.S. security advisers, including five who served during Obama's first term in office, on June 24 called for a stronger deal than the one the administration has outlined in its preliminary deal with Iran.
"Most of us would have preferred a stronger agreement," the security officials said in an open letter released by the Washington Institute.
Like Israel, the deal's biggest critic, the advisers said that "the agreement will not prevent Iran from having a nuclear weapons capability. It will not require the dismantling of Iran's nuclear infrastructure" but rather will only reduce that infrastructure for the next 10 to 15 years.
The letter was signed by Dennis Ross, an adviser on Iran in Obama's first term, as well as David Petraeus, former CIA director and U.S. commander in Iraq; Robert Einhorn, a former member of the U.S. negotiating team with Iran; retired U.S. General James Cartwright; and Gary Samore, an Obama adviser on nuclear policy turned president of the advocacy group United Against Nuclear Iran.
The letter was also signed by Stephen Hadley, a national security adviser to both former President George W. Bush and his brother, Republican presidential contender Jeb Bush.