The operation took place overnight Sunday. The ship Veronica III had been tracked from the Caribbean Sea to the Indian Ocean, where US forces managed to stop it without "incidents."
"The ship attempted to defy President Trump's quarantine - hoping to escape," the Pentagon says.
The Panama-flagged ship was subject to sanctions linked to Iran, the AP news agency reports.
The tanker is one of several the US has seized since December last year. Donald Trump has ordered a blockade against ships carrying oil to and from Venezuela.
