Iran unveils upgraded ballistic missile
Iran has announced a new version of a short range surface-to-surface ballistic missile, the Fateh-110 or Conqueror.
President Mahmoud Ahmadinejad unveiled the upgraded weapon on Tuesday, just weeks after it was test-fired.
He said Iran was seeking to develop its defence capabilities "not in an aggressive context, but as a deterrence".
Speculation continues to build over Israeli plans to attack Iran.
Speaking at a ceremony to unveil the upgraded Fateh-110, President Ahmadinejad said Iran only sought to "defend itself".
"We do not seek progress in the defence industry for conquest," he said. "We want it to defend ourselves, our territory, our existence.
"Secondly, we want it for defending human dignity."
The official Irna news agency said the upgrade included quicker launching, a longer life and use in poor weather conditions.
The Iranian government has made it clear that if it is attacked either by Israel or the US, it will respond in kind, either directly or through proxies.
It is not thought to have the capability to launch a nuclear weapon, but Iran has stockpiled a range of short and medium-range missiles.
In May, Prof Theodore Postol, a leading expert on missile defence technology, told the BBC that without nuclear weapons, the threat from Iran's ballistic missiles was limited.
"There is no realistic threat to troops, cities, oil refineries, and the like from Iranian ballistic missiles. They can simply not carry large enough conventional munitions to do extensive damage on impact, and they lack the accuracy to hit prescribed targets with reliability," he said.
One US blogger recent published what he said were Israeli plans to attack Iran.
Richard Silverstein told the BBC last week he had been given a briefing memo for Israel's security cabinet which outlined what Israel would do to prevent Iran developing nuclear weapons.
Israel's Prime Minister Benjamin Netanyahu has threatened military action against Iran, but officials stress that no final decision has been made.
Earlier this year, the United States also significantly increased its military presence in the Persian Gulf.
Analysts say the move was designed to deter Iran from closing off the Strait of Hormuz, a crucial trade route, and to increase the number of jets capable of striking Iran if concern over its nuclear programme escalated.