TEHRAN (Reuters) - Iran's hard-line rulers sent uncompromising signals to foes at home and abroad on Wednesday, warning of possible legal action against opposition leaders and testing an upgraded missile that could reach Israel.
The United States said the launch of a Sejil 2 missile, with a reported range that would put the Jewish state and U.S. Gulf bases within reach, undermined Iran's claim of peaceful intentions and would be looked upon seriously by the world.
British Prime Minister Gordon Brown said the test boosted the case for tougher sanctions over the oil producer's disputed nuclear program, which the West fears is aimed at making bombs. Tehran says it seeks only to generate electricity.
"This is a matter of serious concern to the international community and it does make the case for us moving further on sanctions," Brown said in Copenhagen.
A senior Obama administration official, speaking on condition of anonymity, said senior diplomats from the major powers negotiating with Iran over its nuclear program were expected to hold a conference call, possibly on Tuesday, to discuss the next steps.
The official said the so-called P5+1 powers -- the permanent members of the U.N. Security Council plus Germany -- will probably be looking "more and more" at applying pressure to get Iran to curb its nuclear ambitions, with the focus moving to the United Nations in New York early next year.
The permanent members of the Security Council are the United States, Russia, China, France and Britain.
Iranian officials have been dismissive of foreign sanctions. A senior Iranian energy official said on Wednesday recent sanctions proposed by U.S. lawmakers aimed at cutting into Iran's gasoline imports will not work.
Iran is the world's fifth-largest oil exporter but lacks enough refining capacity to meet domestic fuel needs, forcing it to import up to 40 percent of its gasoline consumption. That makes it vulnerable to punitive measures targeting the trade.
On Tuesday, the U.S. House of Representatives backed legislation to impose sanctions on foreign companies that help to supply fuel to Iran. The Senate has not yet acted on the measure.
"They cannot succeed," said Hojjatollah Ghanimifard, vice president of investment affairs at the National Iranian Oil Company. "We have a long list of suppliers of gasoline."
Iranian President Mahmoud Ahmadinejad also reiterated Tehran's position that its nuclear program has peaceful goals.
"It is true that Iranian nation has a lot of enemies, but it does not need an atomic bomb to defend itself," Ahmadinejad said in a Danish television interview, highlights of which were carried by the official IRNA news agency.
"Nuclear weapons could not save the Soviet Union from collapse. Iran opposes atomic weapons and supports nuclear disarmament," Ahmadinejad said.
Analysts say political turmoil in Iran since a disputed presidential election in June has further clouded prospects for any resolution of the nuclear dispute. Internal tension has increased since student backers of opposition leader Mirhossein Mousavi clashed in Tehran last week with security forces.
The government and official media have accused opposition supporters of insulting the memory of the Islamic Republic's revered late founder, Ayatollah Ruhollah Khomeini, by tearing up a picture of him during the demonstrations.
The opposition has denied involvement in the reported picture incident, suggesting the authorities were planning to use it as a pretext for a renewed crackdown.
Raising pressure on the reform movement, Iran's judiciary said it had evidence that opposition leaders had fomented trouble after the presidential poll, which Mousavi says was rigged in favor of Ahmadinejad.
"We have enough proof about the leaders of this plot against the system," judiciary head Sadeq Larijani said, according to IRNA.
The authorities have rejected opposition charges of poll fraud and portrayed the biggest anti-government protests since the 1979 revolution as a foreign-backed bid to end clerical rule.
Thousands of Mousavi supporters were detained after the vote, including senior reformers. Most have been freed but more than 80 people have received jail terms of up to 15 years and five have been sentenced to death over the post-vote unrest.
Wednesday's test of a Sejil missile, which Iranian Defense Minister Ahmad Vahidi said could not be destroyed by anti-missile systems due to its high velocity and anti-radar capabilities, drew swift Western condemnation.
But in Washington, Pentagon press secretary Geoff Morrell said the test did not reveal any new capabilities.
"I'm not going to get into the particulars of what our intelligence shows other than to say I don't think there was anything here that was particularly different than what we've seen in the past," Morrell said.
White House spokesman Mike Hammer said the test would "increase the seriousness and resolve of the international community to hold Iran accountable for its continued defiance of its international obligations on its nuclear program."
Vahidi said the test of the Sejil 2 was aimed at boosting deterrent capabilities and posed no threat to the region.
Iran earlier this year said Sejil 2 had a range of 2,000 km (1,250 miles), enabling it to reach Israel and U.S. bases in the region. Neither Israel nor the United States has ruled out military action if diplomacy fails to resolve the nuclear dispute. Iran has vowed to retaliate for any attack.
In October, negotiators offered a deal under which Iran would send most of its low-enriched uranium abroad for further enrichment. However, Tehran has backed away from it, raising the prospect of additional sanctions.
Additional reporting by Reza Derakhshi and Ramin Mostafavi in Tehran and by Reuters reporters in Washington, Copenhagen and Paris; Editing by Will Dunham