The oil tanker Marinera at the Singapore Strait in March. (Photo by Reuters)

Russia has reportedly dispatched a submarine and several naval vessels to escort an oil tanker being pursued by the US Coast Guard in the North Atlantic on Wednesday.

According to reports, the tanker is en route to the Russian port of Murmansk.

US military aircraft were tracked over the North Atlantic earlier in the day, moving towards the tanker, identified as the Marinera.

Two US officials told CBS News that American forces were preparing to board the vessel, with Washington preferring seizure over sinking the vessel.

Footage released by Russia Today, reportedly filmed onboard a tanker, shows a vessel in the distance resembling a US Coast Guard Legend-class cutter.

The ship is currently sailing between Iceland and the British Isles. Washington has accused the vessel of violating US sanctions by transporting Iranian oil.

The tanker`s transit into European waters has coincided with the arrival of around 10 US military transport aircraft and several helicopters in the United Kingdom, raising concerns over a broader military escalation.

Formerly known as Bella 1, the tanker has been renamed Marinera and reportedly reflagged from Guyana to the Russian Federation. The vessel has previously transported Venezuelan crude oil, though it is currently reported to be empty.

Russia`s Foreign Ministry said in a statement that it is "monitoring with concern" the situation surrounding the tanker.

"At present, our vessel is sailing in international waters of the North Atlantic under the state flag of the Russian Federation and in full compliance with international maritime law," the ministry added,

"For reasons unclear to us, the Russian ship is being subjected to increased and clearly disproportionate attention by the US and NATO military, despite its peaceful status," it said, adding that Moscow expects Western states to respect freedom of navigation.

Under international law, vessels sailing under a national flag fall under the protection of that state.

US President Donald Trump said last month that he had ordered a "blockade" of sanctioned oil tankers entering or leaving Venezuela.

On Tuesday, the US military`s Southern Command said on social media that it "remains ready to support US government agency partners in standing against sanctioned vessels and actors transiting through this region."

"Our sea services are vigilant, agile, and postured to track vessels of interest. When the call comes, we will be there," the command said.

US officials told CBS News that Washington could mount an operation similar to one carried out last month, when American forces seized the Skipper, a Guyana-flagged oil tanker, as it was departing Venezuela.

Last month, the US Coast Guard also attempted to board the Marinera in the Caribbean when it was believed to be heading towards Venezuelan waters.

The US operation in the North Atlantic comes days after the United States launched military attacks on Venezuela and kidnapped President Nicolás Maduro in the early hours of Saturday.

Trump has repeatedly accused Venezuela`s government of using commercial vessels to smuggle drugs into the United States - allegations that Caracas has categorically denied, describing them as a pretext to attack the country.