Central Command spokesperson Capt Tim Hawkins said the US military "continues to defend our forces while using restraint during the ongoing ceasefire".
The strikes come as Iranian foreign ministry spokesman Esmail Baqai said some progress has made in talks with the US, but a deal to end the conflict "is not imminent".
Hawkins said the strikes targeted an area near Bandar Abbas, a southern port city and home of an Iranian naval base that sits on the Strait of Hormuz, according to the New York Times.
Iranian state media had earlier reported that local officials in Bandar Abbas were investigating after explosions were heard.
is yet to respond to the latest US strikes. It is unclear what impact they will have on any potential peace agreement between the US and Iran.
At the weekend, President Donald Trump had suggested the sides were close to a deal, but later said he had instructed negotiators "not to rush into" one.
US Secretary of State Marco Rubio also said an agreement could possibly be reached on Monday.
But Baqai responded: "It is correct to say that we have reached a conclusion on a large portion of the issues under discussion... But to say that this means the signing of an agreement is imminent - no-one can make such a claim."
The memorandum of understanding being discussed reportedly involves a 60-day ceasefire extension, the reopening of the Strait of Hormuz and a plan for further negotiations over Iran's nuclear programme.
