Iran's state TV has broadcast footage purporting to show a close encounter between the Revolutionary Guard's navy and the USS Theodore Roosevelt in the strategic Strait of Hormuz in the Persian Gulf, the passageway for nearly a third of all oil traded by sea.
Saturday's footage is likely meant as a show of strength amid new US sanctions on Iran and the Trump administration plans to bring Iranian oil exports down to zero.
In the video, Guard speedboats are seen closing in on the US carrier.
Iranian sailors then warn the Americans over radio communication to "keep well clear" of the Guard patrol boats and say they advise the Americans to "refrain from the threat or use of force in any manner."