President Donald Trump said on Wednesday that no Americans were harmed in the attack by Iran on US bases in Iraq as he offered to embrace peace along with the Iranian leadership, in a significant move to de-escalate the tensions in the Middle East.

"We suffered no casualties. All of our soldiers are safe and only minimal damage was sustained at our military bases," Trump said in an address to the nation from the White House Grand Foyer.

His remarks came hours after Iran launched over a dozen ballistic missiles targeting at least two bases where US military and coalition forces' are stationed in Iraq, which Tehran said was a "slap in the face" of America.

According to Iranian state TV, the attacks were in revenge for the killing of the commander of Iran's powerful Revolutionary Guards, General Qasem Soleimani, in a US drone strike on Friday, which was ordered by Trump.

The Iranian state television claimed that "at least 80 terrorist US soldiers" were killed in the strikes. Some 5,000 US soldiers are in Iraq as part of the international coalition against the IS terror group.

"No Americans were harmed in last night's attack by the Iranian regime," Trump said as he described Gen Soleimani as a "ruthless terrorist."

Trump also vowed that he will never allow Iran to have a nuclear weapon.

"As long as I'm President of the United States, Iran will never be allowed to have a nuclear weapon," Trump said.

In a direct message to the Iranian leaders and the people, Trump said the United States is "ready to embrace peace with all who seek it".

"To the people and leaders of Iran, we want you to have a future and a great future, one that you deserve," Trump said.