Iran's crackdown on dissent over the June 12 election suggests the leadership may be unwilling to consider curbing its nuclear ambitions, a position that would prompt the U.S. to call for tougher international sanctions, Secretary of State Hillary Clinton said.

"Even though we are cautiously pursuing a policy of engagement, we are doing it with our eyes open," Clinton said in an interview with Venezuela's Globovision network. "We understand that, given the problems Iran has just demonstrated, it may not be possible -- in which case we would ask the world to join us in imposing even stricter sanctions on Iran to try to change the behavior of the regime."

Iran will hold trials for some 500 people arrested during protests over the re-election of President Mahmoud Ahmadinejad, Prosecutor General Qorbanali Dorri-Najafabadi was cited as saying today by state-run Press TV. They were among hundreds of thousands of opponents who took to the streets, alleging last month’s vote was rigged. About 2,000 others detained over the rallies have been released, Dorri-Najafabadi said.

Authorities used force against the demonstrators, many of them supporters of the main election challenger, former Prime Minister Mir Hossein Mousavi. As many as 20 people were killed, according to state-run media, while Le Figaro yesterday cited hospital staff members in Tehran as saying at least 92 died.

Ahmadinejad has increased tensions with the West since taking office in August 2005, pursuing a nuclear program that the U.S. and several major allies say is a cover for weapons development. Iran says the work is peaceful and intended to generate electricity. The country is under three sets of United Nations Security Council sanctions for its refusal to halt uranium enrichment.

'Nuclear Weapons'

"We obviously are concerned about Iran's regime, the pursuit of nuclear weapons, which would be very destabilizing in the Middle East and beyond, the support for terrorism that Iran still pursues," Clinton said in the interview, which was televised in Venezuela late yesterday.

The violent suppression of election protests shows that "Iran has not respected its own democracy," she said.

Iran's diplomatic ties have been further strained since the crackdown, jeopardizing the prospect of talks with the West on the nuclear program. Nine Iranian employees of the U.K. Embassy in Tehran were arrested after being accused of fomenting post- election unrest for Britain. The 27-member European Union summoned Iranian ambassadors after a senior cleric said on July 3 that some of the workers would be tried.

'Grave Concern'

Six United Nations experts on human rights expressed "grave concern about reports of killings, ongoing arrests, use of excessive police force and the ill treatment of detainees." The experts, who include Special Rapporteur on Torture Manfred Nowak, urged the government in Tehran to uphold its obligations under international law to protect human rights, according to a joint statement issued yesterday.

The nuclear program has been portrayed by Ahmadinejad's administration as a source of national pride and a necessity for Iran's progress. Strategic decisions on the undertaking are ultimately the responsibility of Supreme Leader Ayatollah Ali Khamenei, who said on July 6 that meddling over the election result by Western countries will have a negative impact on their future relations with Iran.

Ahmadinejad hit out at world powers in a televised speech late yesterday, railing against their "interference and childish acts" and promising that Iran "will not back down in seeking its deserved position and rights," the state-run Fars news agency reported.

EU Envoys

The EU has sent envoys to talk with Iran about its nuclear program. The U.S. severed diplomatic relations with Iran in 1980, after the Islamic Revolution that brought Shiite Muslim clerics to power.

President Barack Obama urged Iran in a March 20 video message to opt for peace over "terror or arms" and forge diplomatic ties with the world. Obama acknowledged there are "serious differences" between the U.S. and Iran, and said his administration wants to engage in diplomacy that addresses the "full range of issues" between the nations.

By Ali Sheikholeslami, Bloomberg, July 8, 2009