Iran's President Mahmoud Ahmadinejad has flatly denied suggestions that his country is building nuclear weapons for military purposes, saying the country's nuclear facilities are dedicated solely to energy generation.
"Some bullying powers are armed with atomic bombs and they claim Iran is seeking such bombs," Ahmadinejad said in response to a November 2011 report from the United Nation's International Atomic Energy Agency. "The Iranian nation does not fear you if it wants to make a bomb, but it does not need a bomb."
Iran has suggested that the U.S. and Israel have conspired to produce Stuxnet, a computer virus that targeted Iran's nuclear facilities. Tehran also expressed anger after a third nuclear scientist was killed in a drive-by bombing.
Ahmadinejad has long proved a controversial leader known for making highly provocative statements. He has asserted that the Holocaust never happened and that Israel should be "wiped off the map." In 2009, he was widely criticized for his swift and violent crackdown on protesters following a disputed election that saw him secure the presidency for a second term.
A national election has been announced for June 14, 2013, and Iranian law prohibits presidents from seeking a third term.
"Our motto is nuclear energy for all and nuclear weapons for none," said Iran's Supreme Leader Ayatollah Khamenei in August 2012 at a summit of the Non-Aligned Movement - a group of developing nations - held in Tehran.
At the event, Khamenei deemed the U.N. Security council a "defunct relic" that was manipulated by the U.S. to "impose its bullying manner on the world."
Khamenei has called the acquisition of nuclear weapons to be a "sin" and said the country is pursuing nuclear technology for energy purposes.
Ehud Barak, the country's defence minister, had long rallied for a pre-emptive strike against Iran but in recent weeks he has shifted his approach. In September 2012, Barak along with Israeli Prime Minister Benjamin Netanyahu called for world powers to establish boundaries for Iran.
"I think what is important is to realize that Iran will not stop unless it sees ... a clear red line," he said.
In response, U.S. Secretary of State Hillary Clinton said the U.S. will not set deadlines for Iran and said negotiations continued to be the favoured approach.
Still, Netanyahu has continued to warn about the potentially dire consequences of Iran gaining nuclear weaponry.
"You know, they're in the last 20 yards, and you can't let them cross that goal line," he said on Meet the Press. "You can't let them score a touchdown, because that would have unbelievable consequences, grievous consequences for the peace and security of us all, of the world really."
U.S. Secretary of State Hillary Clinton has called for continued negotiations with Iran, saying economic sanctions are the preferred method of applying pressure.
Clinton has been rallying support, visiting China and Russia in September 2012. Following her meetings, she said both countries agree that Iran should be stopped from acquiring nuclear weapons. The White House has meanwhile cautioned Iran that the window for resolution "will not remain open indefinitely."
Iran has responded to the sanctions, saying it could block access to the Strait of Hormuz, a major vessel for seaborne oil exports. Diplomatically, U.S.-Iranian ties have been fraught with tension. There have been suggestions that the U.S. was involved in the release of the Stuxnet virus that targeted Iran's nuclear facilities. In October 2011, U.S. officials also said they had foiled an Iranian bid to assassinate the Saudi ambassador to the U.S.
The International Atomic Energy Agency in August 2012 released a report that suggested Iran over the summer months had doubled the number of uranium enrichment centrifuges at its Fordow nuclear facilities. The IAEA also said it suspected a clean-up operation that included "significant ground scaping and landscaping" at the Parchin military base.
In September 2012, Russia, China, the U.S., France, Germany and Britain sponsored an IAEA draft resolution rebuking Iran for its growing uranium enrichment program. The draft called on Tehran to allow IAEA inspectors access to sites. Cuba was the only country to vote against the resolution while Ecuador, Tunisia and Egypt abstained. While the IAEA cannot act on the resolution, it does represent widening disapproval with Iran for their lack of cooperation with UN inspectors.
Nearly a year earlier, in November 2011, the IAEA published startling findings that said Iran was seeking to build and test nuclear weapons covertly. The agency said the report was based on more than 1,000 pages of intelligence gathered by 10 countries and the IAEA.
Iran has denied the allegations made in the report, saying that the IAEA was bowing to U.S. pressures. But many Western powers responded by introducing financial sanctions against the country.
UN chief Ban Ki-moon in late August 2012 urged Iran to take concrete steps in addressing global concerns about the country's nuclear program. He also condemned threats from the U.S. and Israel.
At the summit, the UN leader made a veiled criticism of Iranian President Mahmoud Ahmadinejad, who has denied the Holocaust.
"I strongly reject threats by any member state to destroy another or outrageous attempts to deny historical facts such as the Holocaust," he said. "Claiming that Israel does not have the right to exist or describing it in racist terms is not only wrong but undermines the very principle we all have pledged to uphold."
Iran's supreme leader, Ayatollah Ali Khamenei, meanwhile suggested at the summit that the UN was "sabotaging" his country's nuclear progress.
"Unfortunately, the structure of the UN is a defective one with the biggest bully of all the nations, which has used nuclear weapons (the United States), dominating the Security Council," he said. "The United States knows we are not seeking nuclear weapons and it is only looking for excuses," he said.
Canada's Foreign Affairs Minister John Baird has warned that Iran's leadership is "the single most significant risk to global peace and security today." Baird's comments were made in an Aug. 23, 2012, letter to UN Chief Ban Ki-moon ahead of a Tehran summit.
Earlier in the year, Baird warned that if Iran opted to weaponize its atomic enrichment program, it could move quickly to create a bomb. "They're certainly moving to be able to be in that position, then they could certainly dash to the end which could be done in as few as nine or as many as 18 months," he said in a CBC interview in May 2012.
Canada along with the U.S. and the U.K. introduced sanctions in November 2011, cutting off financial transactions with Iran. Prime Minister Stephen Harper said in a January 2012 interview that he believes Iran is developinig nuclear weapons. He said the regime "frightens" him.
"I've watched and listened to what the leadership in the Iranian regime says, and it frightens me," he said. "In my judgment, these are people who have a particular, you know, a fanatically religious worldview, and their statements imply to me no hesitation about using nuclear weapons if they see them achieving their religious or political purposes. And ... I think that's what makes this regime in Iran particularly dangerous."
Most recently, Baird announced Canada's decision to close its embassy in Iran and expel Iranian diplomats from Canada. He also said that Canada is formally listing Iran as a state sponsor of terrorism. Iranian officials deemed the Canadian decision to be "hasty and extreme".
The European Union has introduced a host of sanctions in a bid to force Iran to comply with IAEA requests. Current sanctions prohibit the EU countries from trading arms, goods and technology related to nuclear enrichment. Investment by Iranian nationals in uranium mining is also blocked. EU countries have also stopped importing crude oil and petroleum products from Iran.
"The EU continues to urge Iran to respond clearly and positively to this offer of negotiations and to demonstrate its readiness to address seriously existing concerns on the nuclear issue, without preconditions," the EU said in an April 2012 release.
Most recently Britain, France and Germany have put forward the case to introduce new sanctions.
"We are working on those sanctions ... quite urgently and I hope we will be able to discuss them further when we meet again in the middle of October," British Foreign Secretary William Hague told Reuters in September 2012.
British Foreign Secretary William Hague has warned Iran's nuclear program could spur a Cold War.
"It is a crisis coming down the tracks," Hague told the Telegraph in February 2012. "Because they are clearly continuing their nuclear weapons programme ... If they obtain nuclear weapons capability, then I think other nations across the Middle East will want to develop nuclear weapons.
Hague has recently called for the EU to introduce harsher sanctions on Iran.
Iran and the U.K. have long maintained a fractious relationship — a bond that came under further strain in late 2011. British Chancellor George Osborne introduced new financial sanctions against Iran following the release of the IAEA report that suggested Iran might be attempting to build nuclear weapons. Iran responded by expelling Dominick Chilcott, the British ambassador in Tehran.
Protesters later stormed the UK embassy in Tehran. U.K. officials accordingly expelled Iranian diplomats from the country and closed the Iranian embassy in London.
In February 2012, Iran said it was suspending oil exports to France and the U.K. in response to sanctions imposed by the E.U. and the U.S.
Russian Foreign Minister Sergey Lavrov has cautioned against an attack on Iran, saying it could lead to "catastrophe."
"I have no doubt that it would pour fuel on a fire which is already smouldering, the hidden smouldering fire of Sunni-Shi'ite confrontation, and beyond that (cause) a chain reaction — I don't know where it would stop," he said at a news conference in Jaunary 2012.
More recently, Lavrov has advised against introducing new sanctions, saying they would only serve to isolate Iran further.
"Our American partners have a prevailing tendency to threaten and increase pressure, adopt ever more sanctions against Syria and against Iran," Lavrov told reporters. "Russia is fundamentally against this, since for resolving problems you have to engage the countries you are having issues with and not isolate them."