The United States says it has seized two tankers linked to Venezuelan oil exports in back-to-back operations in the North Atlantic and the Caribbean.

US forces boarded the Russian-flagged Marinera after a pursuit lasting almost two weeks and as it travelled through the waters between Iceland and Scotland. The British Navy gave logistical support by air and sea.

A second tanker - the M/T Sophia - was accused by the US of conducting illicit activities and boarded in the Caribbean.

The moves come as the US seeks to choke off most exports of Venezuelan crude oil, and just days after its special forces seized Venezuelan President Nicolás Maduro in a lighting raid on his residence in Caracas.

In a post on X, Defence Secretary Pete Hegseth wrote: The blockade of sanctioned and illicit Venezuelan oil remains in FULL EFFECT - anywhere in the world.

Moscow has denounced the seizure of the tanker sailing under its flag, and demanded that the US treat Russians on board properly and permits them to return to Russia quickly.

The transport ministry said it had given the vessel temporary permission to use the Russian flag, adding that no state had the right to use force against vessels properly registered in other states' jurisdictions.

Reports had suggested that Russia had dispatched a submarine to safeguard the vessel, but it appears that US forces were able to board the tanker without facing any resistance.

The White House described the ship as a Venezuelan shadow fleet vessel deemed stateless after flying a false flag and had a judicial order against it.

Venezuela's leadership is co-operating with the US on the second tanker seized in the Caribbean, Secretary of State Marco Rubio said.

Earlier, US President Donald Trump had said that Venezuela - which has the world's largest oil reserves - will be turning over up to 50 million barrels of oil worth some $2.8bn (£2.1bn) to the US.

Rubio said that the US would sell oil that is in Venezuela in the marketplace at market rates and that the US would control how the proceeds were dispersed in a way that benefits the Venezuelan people.

The seizure of the two tankers was announced by the US military in separate posts on social media on Wednesday.

The US European Command said the M/V Bella 1 - using the former name of the Marinera - was boarded for violations of US sanctions. Britain's Ministry of Defence said RAF surveillance aircraft and a naval support vessel, the RFA Tideforce, were among the UK military assets that took part in the operation, following a US request for assistance.

Defence Secretary John Healey said the action was in full compliance with international law, and formed part of global efforts to crack down on sanctions- busting.

According to experts, the US called the ship Bella 1 as a vessel cannot change its flag during a voyage unless there is a real transfer of ownership or change of registry. This legal interpretation under UN maritime law states that a stateless vessel can be boarded by authorities.

The US Southern Command announced on Wednesday that the defence and homeland security departments apprehended a stateless, sanctioned dark fleet motor tanker without incident.

Homeland Security Secretary Kristi Noem stated that in two predawn operations today, the Coast Guard conducted back-to-back meticulously coordinated boarding of two 'ghost fleet' tanker ships. She stated that both seized vessels were either last docked in Venezuela or en route to it.