The brigadier general who leads Iran's aerospace program says its forces launched 13 missiles at bases in Iraq used by US troops early Wednesday "but we were ready to launch hundreds".
Gen Amir Ali Hajizadeh also told Iranian state television his forces simultaneously carried out a cyberattack on a US military monitoring service in Iraq.
He asserted that dozens of US forces were killed and wounded "but we were not after killing anyone in this operation". He said, "We were after hitting the enemy's military machine."
The US, however, has said no Americans were killed in the missile strike.
Meanwhile, a top European Union official is urging Iran's president to avoid "irreversible acts" potentially fatal to the Iran nuclear deal that is aimed at preventing the country from developing nuclear weapons.
European Council president Charles Michel spoke with President Hassan Rouhani ahead of a meeting of EU foreign affairs ministers on Friday to assess the rising tensions between the US and Iran.
According to a European Council statement on Thursday, Rouhani told Michel his country wants to continue a "close cooperation" with the EU.
Iran struck the nuclear deal in 2015 with the United States, France, Germany, Britain, Russia and China but President Donald Trump decided to unilaterally abandon the agreement in 2018, triggering sanctions that have badly hurt Iran's economy.
After the US killed Iran's top general last week, Tehran announced it would no longer respect limits on how many centrifuges it can use to enrich uranium.