The U.S. military's top official has cautioned that Iran may have amassed enough fissile material to construct an atomic weapon, amid renewed rhetorical sparring between Tehran and the West.
"We think they do, quite frankly," Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, told CNN on Sunday.
"And Iran having a nuclear weapon, I've believed for a long time, is a very, very bad outcome for the region and for the world."
Mullen added that Iranian President Mahmoud Ahmadinejad's nuclear ambitions were closer than ever to being realized, confirming a United Nations probe which found that Iran had enriched far more uranium than it had previously let on.
The UN's International Atomic Energy Agency reported on Feb. 19 that Iran had low-balled the actual enrichment figure by about a third, meaning it now had enriched uranium stockpiles of about one ton.
Mullen's warning came a day after Prime Minister Stephen Harper called the Iranian regime "evil" during an interview with the Wall Street Journal.
"It concerns me that we have a regime with both an ideology that is obviously evil, combined with a desire to procure technology to act on that ideology," Harper told the newspaper on Saturday.
"My government is a very strong supporter of the state of Israel and considers the Iranian threats to be absolutely unacceptable and beyond the pale," he added.
The public comments from Western leaders mark a sharp reversal from only a few weeks ago, when U.S. President Barack Obama's administration expressed hope that direct talks with Tehran could thaw decades of frosty relations with Washington.
Still time for diplomacy?
Still, the IAEA said that further purification would be necessary for Iran to successfully manufacture a nuclear weapon.
That sentiment was echoed by U.S. Defence Secretary Robert Gates, who said that Iran still has major hurdles to cross before any nuclear bomb could be built.
"They're not close to a stockpile," Gates told NBC's Meet the Press Sunday. "They're not close to a weapon at this point. And so, there is some time."
Iran, which had seen its regional influence rise with the global price of oil, has insisted that its nuclear program is intended for peaceful energy purposes only.
But Gates noted that plummeting global commodity prices could force Iran to suspend its nuclear program in return for economic privileges with the U.S. and Europe.
"The question is whether you can increase the level of the sanctions and the cost to the Iranians of pursuing that program -- at the same time you show them an open door if they want to engage with the Europeans, with us," Gates said.
"There are economic costs to this program," he added. "They do have economic challenges at home."
Obama and his administration are reviewing the way the U.S. deals with some of its more challenging foreign policy files, including making compromises with Iran and Russia.
On Sunday, the New York Times reported that one plan could see the White House halt plans for proposed U.S. missile sites in the Czech Republic and Poland if Russia helps pressure Tehran into dropping its nuclear program.
U.S. plans to build missile defence sites in former eastern bloc countries has angered Russia, who has seen it as an invasion of its traditional sphere of influence.
