Iran on Sunday accused the United States of giving a "Hollywood version of events" over a recent incident in the Gulf.
The U.S. had alerted that Iranian vessels conducted "harassing" approaches toward six of its ships.
Reacting, the Islamic Revolutionary Guard Corps (IRGC) explained why it increased patrols in the mediterranean sea in Western Asia.
The IRGC, in a statement, said U.S. forces blocked one of its ships in two separate incidents in early April, using "dangerous behaviour while ignoring warnings".
BBC quoted the corps as warning that Iran would respond "decisively" to any miscalculation.
The U.S. Navy posted a video of the latest incident on Twitter.
The tweet read: "11 Iranian #IRGCN vessels repeatedly conducted dangerous & harassing approaches against U.S. naval ships operating in international waters of North Arabian Gulf. U.S. crews took actions deemed appropriate to avoid collision.
"Initial assessments indicate #IRGCN vessels' closest points of approach were 50 yards from #USSLewisBPuller & 10 yards from
@USCG #Maui. There were no injuries during the interaction."
The vessels were involved in a military exercise with U.S. Army Apache attack helicopters.
The Navy, in another statement, said: "The US crews issued multiple warnings via bridge-to-bridge radio, five short blasts from the ships' horns and long-range acoustic noise maker devices, but received no response from the IRGCN.
"After approximately one hour, the IRGCN vessels responded to the bridge-to-bridge radio queries, then manoeuvred away from the US ships and opened distance between them".
It insisted that such "dangerous and provocative actions increased the risk of miscalculation and collision", and negates international maritime conventions or customs.
Since January, there has been tension between the United States and Iran after the killing of military commander, Qassem Soleimani, in a drone attack in Iraq.