US forces have seized an oil tanker off the coast of Venezuela, President Donald Trump said, marking a sharp escalation in Washington's pressure campaign against Nicolás Maduro's government.

"We have just seized a tanker on the coast of Venezuela - a large tanker, very large, the largest one ever seized actually," Trump told reporters at the White House.

Releasing a video of the seizure, Attorney General Pam Bondi described the vessel as a "crude oil tanker used to transport sanctioned oil from Venezuela and Iran".

Caracas swiftly denounced the action, calling it an act of "international piracy". Earlier, President Maduro declared that Venezuela would never become an "oil colony".

The Trump administration accuses Venezuela of funnelling narcotics into the US and has intensified its efforts to isolate President Maduro in recent months.

Venezuela - home to some of the world's largest proven oil reserves - has, in turn, accused Washington of seeking to steal its resources.

Brent crude prices inched higher on Wednesday as news of the seizure stoked short-term supply concerns. Analysts warn the move could threaten shippers and further disrupt Venezuela's oil exports.

US Attorney General Pam Bondi, who leads the US Department of Justice, said the Federal Bureau of Investigation, Department of Defense, Department of Homeland Security, and the US Coast Guard co-ordinated the seizure.

"For multiple years, the oil tanker has been sanctioned by the United States due to its involvement in an illicit oil shipping network supporting foreign terrorist organizations," the nation's top prosecutor wrote on X.

Footage shared by Bondi showed a military helicopter hovering over a large ship, and troops descending on to the deck using ropes. Uniformed men were seen in the clip moving about the ship with guns drawn.

A senior military official told the BBC's US partner CBS that the helicopters used in the operation launched from the USS Gerald Ford, the world's largest aircraft carrier, which was sent to the Caribbean last month.

It involved two helicopters, 10 Coast Guard members and 10 Marines, as well as special forces.

Defence Secretary Pete Hegseth was aware of the operation, and the Trump administration was considering more actions like this, a source told CBS.

When asked by reporters what the US would do with the oil on the tanker, Trump said: "We keep it, I guess... I assume we're going to keep the oil."

Maritime risk company Vanguard Tech identified the vessel as the Skipper and said it believed the ship had been "spoofing" its position - or broadcasting a false location - for a long time.

The US treasury department sanctioned the Skipper in 2022, CBS reported, for alleged involvement in oil smuggling that generated revenue for Hezbollah and the Islamic Revolutionary Guard Corps-Quds Force.

BBC Verify located this tanker on MarineTraffic, which shows it was sailing under the flag of Guyana when its position was last updated two days ago. A statement from Guyana's Maritime Administration Department on Wednesday evening, however, said that the Skipper was "falsely flying the Guyana Flag as it is not registered in Guyana."

The Skipper's port of call log shows it called in Iran, Iraq, and the UAE from 30 June to 9 July this year. Its most recent stop, according to MarineTraffic, was at Soroosh port in Iran on 9 July, BBC Verify has found.

That does not mean that it has not called at multiple other ports since then.

MarineTraffic shows it was last near Iran in mid-September before arriving off the coast of Guyana at the end of October and making minimal further movement since then. This data may be partial or incorrect because of spoofing.

MarineTraffic lists the beneficial owner and operator as Nigeria-based Thomarose Global Ventures Ltd and it lists the registered owner as Marshall Islands-based Triton Navigation Corp.

The Venezuelan government issued a statement denouncing the seizure as a "grave international crime".

Interior Minister Diosdado Cabello called the US "murderers, thieves, pirates".

He referred to Pirates of the Caribbean, but said that while that film's lead character Jack Sparrow was a "hero", he believed "these guys are high seas criminals, buccaneers".

Cabello said this was how the US had "started wars all over the world".

Speaking at a rally earlier on Wednesday, Maduro had a message for Americans opposed to war with Venezuela. It came in the form of a 1988 hit song.

"To American citizens who are against the war, I respond with a very famous song: Don't worry, be happy," Maduro said in Spanish before singing along to the lyrics of the 1988 hit.

"Not war, be happy. Not, not crazy war, not, be happy."

It's unclear if Maduro knew about the seizure of the tanker before this rally.

In recent days, the US has ramped up its military presence in the Caribbean Sea, which borders Venezuela to the north.

The build-up involves thousands of troops and the USS Gerald Ford being positioned within striking distance of Venezuela, BBC Verify reported.

The move has sparked speculation about the potential for some kind of military action.

Since September, the US has conducted at least 22 strikes on boats in the region that the Trump administration says are smuggling drugs. At least 80 people have died in these attacks. (BBC)

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