Donald Trump, the U.S. president, released an iconic video of an airstrike and explosion on Kharg Island and, in a one-line message accompanying it, wrote that Kharg Island, the “energy hub” of the Islamic Republic, is “falling apart.”

He wrote on Truth Social: “Kharg Island is falling apart!!! DJ President.” Mr. Trump did not provide any other details.

Before the war began, Kharg Island handled 90 percent of the Islamic Republic’s oil exports. Mr. Trump has repeatedly threatened to take control of this island, but so far he has not done so.

His message was released on a day when fighting between the two sides resumed after about a month of calm.