"I can confirm that earlier today US forces struck two Iranian launchers on Larak Island. Islamic Revolutionary Guard Corps forces were observed preparing to launch rockets with sea mines into Strait of Hormuz," the US official said.
Iran's Revolutionary Guards said the attack killed and wounded several soldiers and citizens and would be met with a "response and punishment" from Tehran, Iranian state media reported.
Iran's semi-official Tasnim news agency reported the US carried out a drone strike on the island.
US President Donald Trump said last week that all mines had been detonated or removed from the international waters of the Strait of Hormuz and Iran has been told that any ship or boat placing new mines will be destroyed.
The last known US strikes on Iran were in late July, as the war has reached a stalemate in recent weeks with Washington threatening to impose costly sanctions on countries that support Iran.
The US and Israel attacked Iran on February 28 and Iran responded with its own strikes on Israel and Gulf states that host US bases.
The Iran war has now crossed its six-month mark.
US-Israeli strikes on Iran and Israeli attacks on Lebanon have killed thousands and displaced millions.
Eighteen US service members have been killed in the conflict.
The war has led to the blockade of the Strait of Hormuz, which before the conflict used to see a transit of about a fifth of the world's oil barrels consumed.
Earlier on Sunday, a multinational coalition overseen by the US Navy said commercial traffic through the strait remained at "reduced levels".
And a monitoring agency run by the British military said an unknown projectile struck a tanker ship on Saturday north of Khasab, Oman, in the strait.
with Reuters
10°C