"Within the first minute of any attack by enemies against our country, the missile and artillery unit of the ground force is capable of firing 11,000 missiles and shells at targets that are known to us," Gen. Mahmoud Chaharbaghi, the top missile commander of the Revolutionary Guards, said on national TV.
Iran has precise data on the deployment of potential attackers' military bases in the region, he said.
"A possible war will not last long, because within days we will reduce our enemies to ashes. The enemy must ask himself what losses he is prepared to suffer for his stupidity," the commander said.
The commander's comments come four days after United States President George W. Bush's warning that if Iran's nuclear program is not stopped, World War III could break out. The United States has military bases in several countries near Iran, including thousands of troops in Iraq and Afghanistan, which share borders with the Islamic Republic.
In response to Bush's comments, Iranian Foreign Ministry spokesman Mohammad Ali Hosseini said on Thursday: "Statements of this kind reflect America's expansionist goals, which will surely weaken international security and ignite the U.S. government's militarist policy."
Washington, which along with many other Western nations accuses Iran of pursing a secret nuclear weapons program, despite Iranian denials, has refused to rule out military action against the country in the long-running international dispute.
Bush's comments at a White House news conference came a day after President Vladimir Putin's visit to Tehran, where the Russian leader said he saw no evidence that Iran was developing nuclear weapons.
Putin's trip to Iran for a summit of Caspian littoral states, the first visit by a Russian or Soviet leader since Joseph Stalin traveled to Iran in 1943, provoked concerns in the West over increasingly close ties between Moscow and Tehran. The summit resulted in a five-way agreement that no Caspian nations would allow the use of their territories for a military strike against any of them.