Secretary of State Hillary Clinton says she doesn't believe Iran can convince the U.S. and other world powers that its nuclear program is for peaceful purposes, putting Tehran on a course for tougher economic penalties beyond the current "leaky sanctions."
Defense Secretary Robert Gates played down the effectiveness of military strikes against Iran's newly disclosed secret uranium-enriching facility. Gates and Clinton said economic and diplomatic pressure would have a better chance of changing Iranian policies.
"The reality is, there is no military option that does anything more than buy time," he told CNN's "State of the Union" in an interview broadcast Sunday.
"The Iranians are in a very bad spot now because of this deception, in terms of all of the great powers. And there obviously is the opportunity for severe additional sanctions."
The nuclear program, which Iran claims is designed to generate electricity, is at the top of the agenda at a meeting Thursday in Geneva involving diplomats from Iran, the U.S., Britain, France, Russia, China and Germany.
‘Don't assert it, prove it’
The Iranians must "present convincing evidence as to the purpose of their nuclear program. We don't believe that they can present convincing evidence, that it's only for peaceful purposes, but we are going to put them to the test," Clinton told CBS' "Face the Nation."
She told the Iranian government: "Don't assert it, prove it. ... They can't say anything because they've said that for years, but they can open their entire system to the kind of extensive investigation that the facts call for."
"If we don't get the answers that we are expecting and the changes in behavior that we're looking for, then we will work with our partners to move toward sanctions," Clinton added.
Tensions grew with the announcement Sunday that Iran successfully test-fired short-range missiles during military drills by the elite Revolutionary Guard.
Gates emphasized China's key role in winning additional penalties against Iran. The five permanent members of the U.N. Security Council, including China, would have to agree to new sanctions. The United States, Britain and France support additional economic conditions and Russia now appears favorable. But China relies heavily on Iranian oil imports and remains reluctant to give its assent.
"China's participation is clearly important," Gates said.
Gates said further penalties could cause Iran to change its nuclear policies because it already faces serious economic problems.
High unemployment among young Iranians
Clinton spoke of "exploring how you broaden and deepen sanctions. Now sanctions are already in place as you know but like many sanction regimes they're leaky."
The defense chief described the political turmoil under Iran's President Mahmoud Ahmadinejad as "simmering," and noted that unemployment among young people in the country is about 40 percent.
"It's clear in the aftermath of the election that there are some fairly deep fissures in Iranian society and politics and — and probably even in the leadership," he said. "And, frankly, this is one of the reasons why I think additional and especially severe economic sanctions could have some real impact because we know that the sanctions that have already been placed on the country have had an impact."
The Pentagon chief added, "We are seeing some changes or some divisions in the Iranian leadership and in society that we really haven't seen in the 30 years since the revolution."
It is critical that world powers persuade the Iranians that their pursuit of nuclear weapons will undermine their country's security, Gates said.
This week's meeting is the first step to see if Tehran can change policy to the satisfaction of the world's powers. If that fails, Gates said, then "you begin to move in the direction of severe sanctions. ... I think that severe sanctions would have the potential" of changing their policies.
"How long do I think we have? I would say somewhere between one to three years," he told ABC's "This Week."
A senior Obama administration official said Saturday that the U.S. and its partners at the Geneva meeting will insist that Tehran provide "unfettered access" to its previously secret Qom enrichment facility within weeks.
So-called transparency package
The six major powers also will present in the Oct. 1 meeting in Geneva a so-called transparency package covering all of Iran's nuclear activities across the country, the official said. This would include full access for the International Atomic Energy Agency to any and every site, notebooks, computers and documents related to nuclear development, and all scientists.
The official spoke on condition of anonymity in order to discuss plans that are not yet ready to be announced.
But beyond the timeframe of "weeks" for coming clean on Qom, the six countries will not give Iran a specific deadline to provide the information about its overall program, the official said.
The development of such a timeframe will depend on the Iranians' actions in the meeting and directly after it, the official said.
The United States will be represented in Thursday's meeting in Geneva by William Burns, the under secretary of state for political affairs, a career diplomat.
On Saturday, Iran's nuclear chief told state TV that his country would allow the U.N. nuclear agency to inspect Iran's newly revealed and still unfinished uranium enrichment facility. Ali Akbar Salehi did not specify when inspectors from the IAEA could visit. He said the timing would be worked out with the U.N. watchdog.
Earlier Saturday, President Barack Obama offered Iran "a serious, meaningful dialogue" over its disputed nuclear program, while warning Tehran of grave consequences from a united global front.