The tanker, Veronica, was seized in a predawn operation "without incident", the US military's Southern Command says.

The US has seized a sixth tanker in the Caribbean Sea in its ongoing efforts to control exports of Venezuelan oil, officials say.

The vessel, Veronica, was boarded in a predawn operation “without incident” as it was defying President Donald Trump’s “quarantine of sanctioned vessels”, said the US military.

“The only oil leaving Venezuela will be oil that is coordinated properly and lawfully,” the Southern Command said.

Since the US military strikes on Venezuela and seizure of its president Nicolás Maduro this month, Trump has said he plans to tap into the country’s huge oil reserves.

“The Veronica is the latest tanker operating in defiance of President Trump’s established quarantine of sanctioned vessels in the Caribbean,” US Southern Command said in a post on social media.