A senior official said the entire crew of the Stena Impero oil tanker was in good health.
The Marine Corps' Light Marine Air Defense Integrated System, known as LMADIS, jammed an Iranian drone.
Iran's Revolutionary Guard forces seized a foreign oil tanker accused of smuggling oil, Iran's state TV reported.
Iran's foreign minister said Wednesday that his country has no choice but to manufacture missiles for defense purposes.
An oil tanker from the UAE entered Iranian waters and turned off its tracker two days ago.
Marine Gen. Joseph Dunford said the Pentagon has developed a specific plan.
A senior Spanish official said the operation was requested by the United States.
U.S. surveillance and reconnaissance flights haven't stopped or been scaled back since Iran shot down a Navy RQ-4 last week.
Iranian leaders said they refrained from shooting down a P-8 transiting in the region, and instead shot down the Global Hawk.
Iran sharply criticized new U.S. sanctions targeting the Islamic Republic's supreme leader and other top officials.