President Mahmoud Ahmadinejad says Iran has tested a missile that western analysts say could hit Israel and US bases in the Gulf.
The test was announced on Wednesday - the same day that campaigning for a presidential election on 12 June officially started.
State television showed the Sejil-2 surface-to-surface missile soaring into the sky in the northern Semnan province, leaving a vapour trail. The stated range of Sejil is some 2000km.
The move is likely to fuel Western concern about Tehran's nuclear ambitions.
Addressing a rally in Semnan, President Ahmadinejad said Iran had the power to send any attacker "to hell."
He said the missile used advanced technology and landed exactly on an unspecified target.