Iran on Monday test-fired its long-range Shahab-3 missile which it says could hit targets in arch-foe Israel, as the Revolutionary Guards staged missile war games for the second straight day.
The exercise comes at a time of heightened tension with the West after the UN nuclear watchdog revealed on Friday that the Islamic republic was building a second uranium enrichment plant.
On Sunday, the Guards launched the missile manoeuvres marking "Sacred Defence" week, which commemorates the start of the eight-year Iran-Iraq war in the 1980s.
Iran's English-language state-owned Press TV channel on Monday broadcast footage of the Shahab-3 being fired in desert terrain.
Iran says the weapon has a range of 1,300-2,000 kilometres (800-1,240 miles), which would put Israel, most Arab states and parts of Europe including much of Turkey within its range.
On Sunday, the Guards fired several short- and medium-range missiles, some with multiple warheads, state media reported.
The medium-range Shahab-1 and Shahab-2, with a range of between 300 kilometres and 700 kilometres, were successfully launched, the Guards' air force commander Hossein Salami said.
"The missiles shot have precisely hit the targets," he said.
Earlier, the Guards test-fired three types of short-range missile -- the Tondar-69, Fateh-110 and Zelzal. All three weapons, powered by solid fuel, have a range of between 100 and 400 kilometres.
On Monday, Salami issued a stern warning to Iran's foes.
"Our response will be strong and destructive to those who threaten the existence, independence, freedom and values of our regime. They will regret it," the official IRNA news agency quoted him as saying.
He said the missile exercise was aimed at practising for "long wars, moving the missile installations from one point to another as well as simultaneous and non-simultaneous shots at convergent and divergent targets."
On Sunday, Salami dismissed Israel as a potential threat, saying "that regime is not in a position that we need to comment about threats from it."
The manoeuvres come after US President Barack Obama earlier this month scrapped his predecessor George W. Bush's plan to deploy missile interceptors in Poland and a powerful tracking radar in the Czech Republic by 2013.
Obama said he had decided to replace the shield with a more mobile system using mainly sea-based interceptors.
In taking the decision, Obama emphasised the threat of Iran's short-range and medium-range missiles instead of the potential danger of its longer-range weapons.
The White House said the intelligence community now believed Iran was developing shorter-range missiles "more rapidly than previously projected," while progressing more slowly than expected with intercontinental missiles.
Iran has in the past threatened to target US bases in the region and to block the strategic Gulf Strait of Hormuz waterway for oil tankers if its nuclear sites are attacked.
Israel and the United States have never ruled out a military option to thwart Iran's nuclear drive, which they suspect of having a military aim despite Tehran's denial.
On Friday, the International Atomic Energy Agency (IAEA) said Iran was building a second uranium enrichment plant, sparking concern by Western leaders.
On Sunday, Iran's nuclear chief Ali Akbar Salehi vowed that Tehran will enrich uranium only up to the five percent level -- much lower than bomb-grade requirement, suggesting Tehran's atomic drive had peaceful aims.
Uranium enrichment lies at the centre of fears over Iran's controversial atomic work as the process to make nuclear fuel can also be used to make the fissile core of an atom bomb in much higher purifications of over 90 percent.
But US Secretary of State Hillary Clinton, in an interview with CBS network, said "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 on October 1."
Iran and world powers meet in Geneva on Thursday to discuss Tehran's disputed atomic programme.